Saccharomyces Boulardii

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Saccharomyces boulardii is a yeast, which is a type of fungus. Saccharomyces boulardii was previously identified as a unique species of ... be a strain of Saccharomyces cerevisiae (baker's yeast). Saccharomyces boulardii is used as medicine. Saccharomyces boulardii is most ...

Clinical Efficacy Comparison of Saccharomyces Boulardii and Lactic Acid as Probiotics in Acute Pediatric Diarrhea.

Science.gov (United States)

Asmat, Shakila; Shaukat, Fouzia; Asmat, Raheela; Bakhat, Hafiz Faiq Siddique Gul; Asmat, Tauseef M

2018-03-01

To compare the efficacy of Saccharomyces boulardii and lactic acid producing probiotics in addition to usual treatment regimen to cure diarrhea among children (6 months to 5 years of age). Randomized controlled trial. Department of Pediatrics, Sheikh Zayed Hospital, Lahore, from February to July 2015. Children suffering from acute diarrhea were orally administered Saccharomyces boulardii and lactic acid producing probiotics for 5 days. The efficacy of administered probiotics was monitored. Patients were given Saccharomyces boulardii and lactic acid producing probiotics randomly to remove the bias. Two hundred patients randomly selected for trials; out of which, 100 were treated with Saccharomyces boulardii while the other 100 were supplemented with lactic acid concomitantly along with conventional diarrhea treatment. Results indicated that Saccharomyces boulardii treatment group has significantly higher efficacy rate (45%) compared to lactic acid producing probiotics (26%). This study concluded that Saccharomyces boulardii has a better efficacy compared to lactic acid and may be adopted as a probiotic of choice.

Investigation of autonomous cell cycle oscillation in Saccharomyces cerevisiae

DEFF Research Database (Denmark)

Hansen, Morten Skov

2007-01-01

Autonome Oscillationer i kontinuert kultivering af Saccharomyces cerevisiae Udgangspunktet for dette Ph.d. projekt var at søge at forstå, hvad der gør det muligt at opnå multiple statiske tilstande ved kontinuert kultivering af Saccharomyces cerevisiae med glukose som begrænsende substrat...

Dynamics of the Saccharomyces cerevisiae Transcriptome during Bread Dough Fermentation

Science.gov (United States)

Aslankoohi, Elham; Zhu, Bo; Rezaei, Mohammad Naser; Voordeckers, Karin; De Maeyer, Dries; Marchal, Kathleen; Dornez, Emmie

2013-01-01

The behavior of yeast cells during industrial processes such as the production of beer, wine, and bioethanol has been extensively studied. In contrast, our knowledge about yeast physiology during solid-state processes, such as bread dough, cheese, or cocoa fermentation, remains limited. We investigated changes in the transcriptomes of three genetically distinct Saccharomyces cerevisiae strains during bread dough fermentation. Our results show that regardless of the genetic background, all three strains exhibit similar changes in expression patterns. At the onset of fermentation, expression of glucose-regulated genes changes dramatically, and the osmotic stress response is activated. The middle fermentation phase is characterized by the induction of genes involved in amino acid metabolism. Finally, at the latest time point, cells suffer from nutrient depletion and activate pathways associated with starvation and stress responses. Further analysis shows that genes regulated by the high-osmolarity glycerol (HOG) pathway, the major pathway involved in the response to osmotic stress and glycerol homeostasis, are among the most differentially expressed genes at the onset of fermentation. More importantly, deletion of HOG1 and other genes of this pathway significantly reduces the fermentation capacity. Together, our results demonstrate that cells embedded in a solid matrix such as bread dough suffer severe osmotic stress and that a proper induction of the HOG pathway is critical for optimal fermentation. PMID:24056467

Dynamics of the Saccharomyces cerevisiae transcriptome during bread dough fermentation.

Science.gov (United States)

Aslankoohi, Elham; Zhu, Bo; Rezaei, Mohammad Naser; Voordeckers, Karin; De Maeyer, Dries; Marchal, Kathleen; Dornez, Emmie; Courtin, Christophe M; Verstrepen, Kevin J

2013-12-01

The behavior of yeast cells during industrial processes such as the production of beer, wine, and bioethanol has been extensively studied. In contrast, our knowledge about yeast physiology during solid-state processes, such as bread dough, cheese, or cocoa fermentation, remains limited. We investigated changes in the transcriptomes of three genetically distinct Saccharomyces cerevisiae strains during bread dough fermentation. Our results show that regardless of the genetic background, all three strains exhibit similar changes in expression patterns. At the onset of fermentation, expression of glucose-regulated genes changes dramatically, and the osmotic stress response is activated. The middle fermentation phase is characterized by the induction of genes involved in amino acid metabolism. Finally, at the latest time point, cells suffer from nutrient depletion and activate pathways associated with starvation and stress responses. Further analysis shows that genes regulated by the high-osmolarity glycerol (HOG) pathway, the major pathway involved in the response to osmotic stress and glycerol homeostasis, are among the most differentially expressed genes at the onset of fermentation. More importantly, deletion of HOG1 and other genes of this pathway significantly reduces the fermentation capacity. Together, our results demonstrate that cells embedded in a solid matrix such as bread dough suffer severe osmotic stress and that a proper induction of the HOG pathway is critical for optimal fermentation.

Photoreactivity in Saccharomyces cerevisiae cells after irradiation with 25 MeV electrons

International Nuclear Information System (INIS)

Tsyb, T.S.; Seleva, N.G.; Myasnik, M.N.; Kabakova, N.M.

1986-01-01

Significant photoreactivation was noted in radio- and UV-sensitive rad-mutants of Saccharomyces cerevisiae cells exposed to 25 MeV electrons. In order to make the photoreactivable damage be manifest anoxic conditions of irradiation should be chosen as optimal ones. It was shown that the low oxygen effect was partially associated with the photoreactivable damage involved in the lethal effect of ionizing radiation

Effect of 60 Co gamma radiation on trehalose level of Saccharomyces boulardii cells

International Nuclear Information System (INIS)

Santos, Raquel Gouvea dos; Neves, Maria Jose; Duarte, Rinaldo; Nicoli, Jacques R.

1996-01-01

The medicine Floratil used for diarrhea treatment is composed by lyophilized yeast cells of Saccharomyces boulardii. The action mechanism of this product is unknown. The efficacy of S. boulardii depends on its viability. The increase in the trehalose level in S. cerevisiae cells submitted to a previous sub-lethal level heat shock results in resistance to a lethal shock. The aim of this work was to study weather the cell trehalose level is involved also in the resistance of gamma irradiation. It was noted that the yeast cells surviving to gamma irradiation had more trehalose level than control cells. Apparently there is a positive correlation between of trehalose level and gamma irradiation resistance of S.boulardii cells. (author)

Improved ethanol production from whey Saccharomyces cerevisiae using permeabilized cells of Kluyveromyces marxianus

Energy Technology Data Exchange (ETDEWEB)

Rosenberg, M [Slovak Technical Univ., Bratislava (Slovakia). Dept. of Biochemical Technology; Tomaska, M [Slovak Technical Univ., Bratislava (Slovakia). Dept. of Biochemical Technology; Kanuch, J [Slovak Technical Univ., Bratislava (Slovakia). Dept. of Biochemical Technology; Sturdik, E [Slovak Technical Univ., Bratislava (Slovakia). Dept. of Biochemical Technology

1996-12-31

Permeabilized cells of Kluyveromyces marxianus CCY eSY2 were tested as the source of lactase in the ethanol fermentation of concentrated deproteinized whey (65-70 g/l lactose) by Saccharomyces cerevisiae CCY 10-13-14. Rapid lactose hydrolysis by small amounts of permeabilized cells following the fermentation of released glucose and galactose by S. cerevisiae resulted in a twofold enhancement of the overall volumetric productivity (1.03 g/lxh), compared to the fermentation in which the lactose was directly fermented by K. marxianus. (orig.)

Bioethanol production from starchy biomass by direct fermentation using saccharomyces diastaticus in batch free and immobilized cell systems

Energy Technology Data Exchange (ETDEWEB)

Kilonzo, P.M.; Margaritis, A. [University of Western Ontario, London, ON (Canada). Dept. of Chemical and Biochemical Engineering; Yu, J.; Ye, Q. [East China Univ. of Science and Technology, Shanghai (China). Biochemical Engineering Research Inst. and State Key Lab

2006-07-01

The feasibility of using amylolytic yeasts for the direct fermentation of starchy biomass to ethanol was discussed. Although amylolytic yeasts such as Saccharomycopsis, Lipomyces, and Schwaniomyces secrete both {alpha}-amylase and glucoamylase enzymes that synergistically enhance starch degradation, they are not suitable for industrial bio-ethanol production because of low tolerance for ethanol and slow fermentation rate. For that reason, this study examined the direct ethanol fermentation of soluble starch or dextrin with the amylolytic yeast Saccharomyces diastaticus in batch free and immobilized cells systems. Saccharomyces diastaticus secretes glucoamylase and can therefore assimilate and ferment starch and starch-like biomass. The main focus of the study was on parameters leading to higher ethanol yields from high concentration of dextrin and soluble starch using batch cultures. A natural attachment method was proposed in which polyurethane foam sheets were used as the carrier for amylolytic yeasts immobilization in ethanol fermentations. The support was chosen because it was inexpensive, autoclavable, pliable and could be tailored to suit process requirements regarding net surface charge, shape and size. It was found that Saccharomyces diastaticus was very efficient in terms of fermentation of high initial concentrations of dextrin or soluble starch. Higher concentrations of ethanol were produced. In batch fermentations, the cells fermented high dextrin concentrations more efficiently. In particular, in batch fermentation, more than 92 g-L of ethanol was produced from 240 g-L of dextrin, at conversion efficiency of 90 per cent. The conversion efficiency decreased to 60 per cent but a higher final ethanol concentration of 147 g/L was attained with a medium containing 500 g/L of dextrin. In an immobilized cell bioreactor, Saccharomyces diastaticus produced 83 g/L of ethanol from 240 g/L of dextrin, corresponding to ethanol volumetric productivity of 9.1 g

Altering the Rate of Mitosis by Introducing Low-Gigahertz Radiation to Saccharomyces cerevisiae Cells

Science.gov (United States)

Garg, S.; Ashby, C.

2017-12-01

This experiment aims to assess the impact of low-frequency radiation (from common technological tools such as cell phones, scanners, and wifi) on the mitotic rates of cells. In particular, the focus of the study was on the growth and development of Saccharomyces cerevisiae cultures that were exposed to radio waves from a wifi router, which were then compared to a cohort of the same species without exposure. Though routers emit a low gigahertz frequency, they are categorized as Group 2B radiation (possibly carcinogenic) by the International Agency for Research on Cancer of the World Health Organization, signifying that constant exposure poses a potential risk to humans. Twelve agar dishes of active Saccharomyces cerevisiae solution were prepared, with six dishes acting as the control under no added radiation and six acting as the experimental group under 2.4 GHz of radiation due to their proximity to the router. Data on how many cultures proliferated in each dish was collected every three days, with the experiment running for a total of twelve days. All subjects experienced growth curves until day 9 when the experimental group's growth peaked with an average of 62 colonies/dish. Three of the six dishes in this group lost colonies in the following three days, leaving the experimental group with an average of 61 colonies/dish on day 12, while the control group was still increasing by day 12 with an average of 48 colonies/dish, with only one dish undergoing a loss of colonies. Exposing the Saccharomyces cerevisiae cells to low grade radiation resulted in accelerated mitosis, and though the experimental group faced colony death after nine days, the loss was likely due to overpopulation in the dish.

Biological effectiveness of pulsed and continuous neutron radiation for cells of yeast Saccharomyces

International Nuclear Information System (INIS)

Tsyb, T.S.; Komarova, E.V.; Potetnya, V.I.; Obaturov, G.M.

2001-01-01

Data are presented on biological effectiveness of fast neutrons generated by BR-10 reactor (dose rate up to 3.8 Gy/s) in comparison with neutrons of pulsed BARS-6 reactor (dose rate ∼6x10 6 Gy/s) for yeast Saccharomyces vini cells of a wild type Menri 139-B and radiosensitive Saccharomyces cerevisiae (rad52/rad52; rad54/rad54) mutants which are defective over different systems of DNA reparation. Value of relative biological efficiency (RBE) of continuous radiation for wild stam is from 3.5 up to 2.5 when survival level being 75-10 %, and RBE of pulsed neutron radiation is in the limits of 2.0-1.7 at the same levels. For mutant stam the value of RBE (1.4-1.6) of neutrons is constant at all survival levels and does not depend on dose rate [ru

Isolation of beta-glucan from the cell wall of Saccharomyces cerevisiae.

Science.gov (United States)

Shokri, Hojjatollah; Asadi, Farzad; Khosravi, Ali Reza

2008-03-20

Beta-glucan, one of the major cell wall components of Saccharomyces cerevisiae (S. cerevisiae), has been found to enhance immune functions. At present study, we developed an optimal procedure to extract and purify beta-glucan. At first, yeast cells were grown in sabouraud dextrose agar and then cultured in yeast extract-peptone-glucose (YPG) broth. After incubation, cells were harvested, washed and disrupted by means of sonication method. The obtained cell walls were used to prepare alkali-soluble beta-glucan (glucan-S1). In this regard, 2% sodium hydroxide (NaOH) and 3% acetic acid were used in alkaline-acid extraction, respectively. This preparation contained 2.4% protein. In the next step, DEAE sephacel chromatography was used to remove remaining proteins (glucan-S2). Subsequently this preparation was applied into concanavalin-A sepharose column to remove manann. Finally, beta-glucan free of mannoprotein complexes was prepared (glucan-S3).

Ultraviolet-endonuclease activity in cell extracts of Saccharomyces cerevisiae mutants defective in excision of pyrimidine dimers

International Nuclear Information System (INIS)

Bekker, M.L.; Kaboev, O.K.; Akhmedov, A.T.; Luchkina, L.A.

1980-01-01

Cell-free extracts of ultraviolet-sensitive mutants of Saccharomyces cerevisiae defective in excision of pyrimidine dimers, rad1, rad2, rad3, rad4, rad10, and rad16, as well as the extracts of the wild-type strain RAD+, display ultraviolet-endonuclease activity

Targeting population heterogeneity in Saccharomyces cerevisiae batch fermentation for optimal cell factories

DEFF Research Database (Denmark)

Heins, Anna-Lena; Lencastre Fernandes, Rita; Lundin, L.

)). Significant gradients of e.g. dissolved oxygen, substrates, and pH are typically observed in many industrial scale fermentation processes. Consequently, the microbial cells experience rapid changes in environmental conditions as they circulate throughout the reactor, which might pose stress on the cells...... and affect their metabolism and consequently affect the heterogeneity level of the population. To further investigate these phenomena and gain a deeper understanding of population heterogeneity, Saccharomyces cerevisiae growth reporter strains based on the expression of green fluorescent protein (GFP) were...... environmental factors on heterogeneity level and amount of living cells. A highly dynamic behavior with regard to subpopulation distribution during the different growth stages was seen for the batch cultivations. Moreover, it could be demonstrated that the glucose concentration had a clear influence...

Influence of organic acids and organochlorinated insecticides on metabolism of Saccharomyces cerevisiae

Directory of Open Access Journals (Sweden)

Pejin Dušanka J.

2005-01-01

Full Text Available Saccharomyces cerevisiae is exposed to different stress factors during the production: osmotic, temperature, oxidative. The response to these stresses is the adaptive mechanism of cells. The raw materials Saccharomyces cerevisiae is produced from, contain metabolism products of present microorganisms and protective agents used during the growth of sugar beet for example the influence of acetic and butyric acid and organochlorinated insecticides, lindan and heptachlor, on the metabolism of Saccharomyces cerevisiae was investigated and presented in this work. The mentioned compounds affect negatively the specific growth rate, yield, content of proteins, phosphorus, total ribonucleic acids. These compounds influence the increase of trechalose and glycogen content in the Saccharomyces cerevisiae cells.

Cell-surface display of enzymes by the yeast Saccharomyces cerevisiae for synthetic biology.

Science.gov (United States)

Tanaka, Tsutomu; Kondo, Akihiko

2015-02-01

In yeast cell-surface displays, functional proteins, such as cellulases, are genetically fused to an anchor protein and expressed on the cell surface. Saccharomyces cerevisiae, which is often utilized as a cell factory for the production of fuels, chemicals, and proteins, is the most commonly used yeast for cell-surface display. To construct yeast cells with a desired function, such as the ability to utilize cellulose as a substrate for bioethanol production, cell-surface display techniques for the efficient expression of enzymes on the cell membrane need to be combined with metabolic engineering approaches for manipulating target pathways within cells. In this Minireview, we summarize the recent progress of biorefinery fields in the development and application of yeast cell-surface displays from a synthetic biology perspective and discuss approaches for further enhancing cell-surface display efficiency. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permission@oup.com.

Incorporating Protein Biosynthesis into the Saccharomyces cerevisiae Genome-scale Metabolic Model

DEFF Research Database (Denmark)

Olivares Hernandez, Roberto

Based on stoichiometric biochemical equations that occur into the cell, the genome-scale metabolic models can quantify the metabolic fluxes, which are regarded as the final representation of the physiological state of the cell. For Saccharomyces Cerevisiae the genome scale model has been construc......Based on stoichiometric biochemical equations that occur into the cell, the genome-scale metabolic models can quantify the metabolic fluxes, which are regarded as the final representation of the physiological state of the cell. For Saccharomyces Cerevisiae the genome scale model has been...

SWITCH: a dynamic CRISPR tool for genome engineering and metabolic pathway control for cell factory construction in Saccharomyces cerevisiae.

Science.gov (United States)

Vanegas, Katherina García; Lehka, Beata Joanna; Mortensen, Uffe Hasbro

2017-02-08

The yeast Saccharomyces cerevisiae is increasingly used as a cell factory. However, cell factory construction time is a major obstacle towards using yeast for bio-production. Hence, tools to speed up cell factory construction are desirable. In this study, we have developed a new Cas9/dCas9 based system, SWITCH, which allows Saccharomyces cerevisiae strains to iteratively alternate between a genetic engineering state and a pathway control state. Since Cas9 induced recombination events are crucial for SWITCH efficiency, we first developed a technique TAPE, which we have successfully used to address protospacer efficiency. As proof of concept of the use of SWITCH in cell factory construction, we have exploited the genetic engineering state of a SWITCH strain to insert the five genes necessary for naringenin production. Next, the naringenin cell factory was switched to the pathway control state where production was optimized by downregulating an essential gene TSC13, hence, reducing formation of a byproduct. We have successfully integrated two CRISPR tools, one for genetic engineering and one for pathway control, into one system and successfully used it for cell factory construction.

Intracellular Signal Triggered by Cholera Toxin in Saccharomyces boulardii and Saccharomyces cerevisiae

Science.gov (United States)

Brandão, Rogelio L.; Castro, Ieso M.; Bambirra, Eduardo A.; Amaral, Sheila C.; Fietto, Luciano G.; Tropia, Maria José M.; Neves, Maria José; Dos Santos, Raquel G.; Gomes, Newton C. M.; Nicoli, Jacques R.

1998-01-01

As is the case for Saccharomyces boulardii, Saccharomyces cerevisiae W303 protects Fisher rats against cholera toxin (CT). The addition of glucose or dinitrophenol to cells of S. boulardii grown on a nonfermentable carbon source activated trehalase in a manner similar to that observed for S. cerevisiae. The addition of CT to the same cells also resulted in trehalase activation. Experiments performed separately on the A and B subunits of CT showed that both are necessary for activation. Similarly, the addition of CT but not of its separate subunits led to a cyclic AMP (cAMP) signal in both S. boulardii and S. cerevisiae. These data suggest that trehalase stimulation by CT probably occurred through the cAMP-mediated protein phosphorylation cascade. The requirement of CT subunit B for both the cAMP signal and trehalase activation indicates the presence of a specific receptor on the yeasts able to bind to the toxin, a situation similar to that observed for mammalian cells. This hypothesis was reinforced by experiments with 125I-labeled CT showing specific binding of the toxin to yeast cells. The adhesion of CT to a receptor on the yeast surface through the B subunit and internalization of the A subunit (necessary for the cAMP signal and trehalase activation) could be one more mechanism explaining protection against the toxin observed for rats treated with yeasts. PMID:9464394

Ferrofluid modified Saccharomyces cerevisiae cells for biocatalysis

Czech Academy of Sciences Publication Activity Database

Šafaříková, Miroslava; Maděrová, Zdeňka; Šafařík, Ivo

2009-01-01

Roč. 42, - (2009), s. 521-524 ISSN 0963-9969 R&D Projects: GA MPO 2A-1TP1/094; GA MŠk(CZ) OC 157 Institutional research plan: CEZ:AV0Z60870520 Keywords : Saccharomyces cerevisiae * magnetic fluid * hydrogen peroxide Subject RIV: EI - Biotechnology ; Bionics Impact factor: 2.414, year: 2009

Lactose/whey utilization and ethanol production by transformed Saccharomyces cerevisiae cells.

Science.gov (United States)

Porro, D; Martegani, E; Ranzi, B M; Alberghina, L

1992-04-05

Strains of Saccharomyces cerevisiae transformed with a multicopy expression vector bearing both the Escherichia coli beta-galactosidase gene under the control of the upstream activating sequence of the GAL1-10 genes and the GAL4 activator gene release part of beta-galactosidase in the growth medium. This release is due to cell lysis of the older mother cells; the enzyme maintains its activity in buffered growth media. Fermentation studies with transformed yeast strains showed that the release of beta-galactosidase allowed an efficient growth on buffered media containing lactose as carbon source as well as on whey-based media. The transformed strains utilized up to 95% of the lactose and a high growth yield was obtained in rich media. High productions of ethanol were also observed in stationary phase after growth in lactose minimal media.

Effect of Ethanol Stress on Fermentation Performance of Saccharomyces cerevisiae Cells Immobilized on Nypa fruticans Leaf Sheath Pieces

Directory of Open Access Journals (Sweden)

Hoang Phong Nguyen

2015-01-01

Full Text Available The yeast cells of Saccharomyces cerevisiae immobilized on Nypa fruticans leaf sheath pieces were tested for ethanol tolerance (0, 23.7, 47.4, 71.0 and 94.7 g/L. Increase in the initial ethanol concentration from 23.7 to 94.7 g/L decreased the average growth rate and concentration of ethanol produced by the immobilized yeast by 5.2 and 4.1 times, respectively. However, in the medium with initial ethanol concentration of 94.7 g/L, the average growth rate, glucose uptake rate and ethanol formation rate of the immobilized yeast were 3.7, 2.5 and 3.5 times, respectively, higher than those of the free yeast. The ethanol stress inhibited ethanol formation by Saccharomyces cerevisiae cells and the yeast responded to the stress by changing the fatty acid composition of cellular membrane. The adsorption of yeast cells on Nypa fruticans leaf sheath pieces of the growth medium increased the saturated fatty acid (C16:0 and C18:0 mass fraction in the cellular membrane and that improved alcoholic fermentation performance of the immobilized yeast.

Cell-to-cell contact and antimicrobial peptides play a combined role in the death of Lachanchea thermotolerans during mixed-culture alcoholic fermentation with Saccharomyces cerevisiae

DEFF Research Database (Denmark)

Kemsawasd, Varongsiri; Branco, Patrícia; Almeida, Maria Gabriela

2015-01-01

The roles of cell-to-cell contact and antimicrobial peptides in the early death of Lachanchea thermotolerans CBS2803 during anaerobic, mixed-culture fermentations with Saccharomyces cerevisiae S101 were investigated using a commercially available, double-compartment fermentation system separated ...

Influence of free radicals generated by gamma irradiation on the trehalose levels in Saccharomyces boulardii leaven cells

International Nuclear Information System (INIS)

Martins, Flaviano dos Santos; Vianna, Cristina Roscoe; Minas Gerais Univ, Belo Horizonte, MG; Neves, Maria Jose

2002-01-01

Lyophilized cells of yeast Saccharomyces boulardii were submit to the gamma irradiation ( 60 Cobalt). It was noted that the yeast cells surviving to gamma irradiation had more trehalose than control cells. The incubation of cells with H 2 0 2 induces the synthesis of trehalose but the exposition to CdCl 2 induces the accumulation of trehalose only in low concentrations. Apparently there is a positive correlation between of trehalose level and gamma irradiation resistance of S. boulardii cells. It was not observed any correlation with the level of trehalose determined and the oxidative stress tested. (author)

Evidence that a recombinationless strain, rad 51, of Saccharomyces cerevisiae lacks the budding cell resistance to γ-rays

International Nuclear Information System (INIS)

Hama-Inaba, Hiroko; Saeki, Tetsuya

1975-01-01

The radiosensitivities of a wild-type and x-ray sensitive mutant, rad 51 (defective in genetic recombination) of Saccharomyces cerevisiae to γ-rays were compared, using non-synchronized and partially synchronized cultures. The rad 51 cells, either haploid or diploid, showed only very small changes in radiosensitivity during cell growth, whereas the wild-type cells, especially haploid, showed the well-known budding resistance. The heterozygous (wild/rad 51) diploid cells showed in a survival curve a remarkable budding resistance and sigmoidal inactivation kinetics similar to those of wild-type homozygous diploid cells. (author)

[Fluorescence polarization used to investigate the cell membrane fluidity of Saccharomyces cerevisiae treated by pulsed electric field].

Science.gov (United States)

Zhang, Ying; Zeng, Xin-An; Wen, Qi-Biao; Li, Lin

2008-01-01

To know the lethal mechanism of microorganisms under pulsed electric field treatment, the relationship between the inactivation of Saccharomyces cerevisiae (CICC1308) cell and the permeability and fluidity changes of its cell membrane treated by pulsed electric field (0-25 kV x cm(-1), 0-266 ms) was investigated. With 1,6-diphenyl-1,3,5-hexatriene (DPH) used as a probe, the cell membrane fluidity of Saccharomyces cerevisiae treated by pulsed electric field was expressed by fluorescence polarization. Results showed that the cell membrane fluidity decreases when the electric flied strength is up to 5 kV x cm(-1), and decreases with the increase in electric field strength and treatment time. The plate counting method and ultraviolet spectrophotometer were used to determine the cell viability and to investigate the cell membrane permeability, respectively, treated by pulsed electric field. Results showed that the lethal ratio and the content of protein and nucleic acid leaked from intracellular plasma increased with the increase in the electric field strength and the extension of treatment time. Even in a quite lower electric field of 5 kV x cm(-1) with a tiny microorganism lethal level, the increase in UV absorption value and the decrease in fluidity were significant. It was demonstrated that the cell membrane fluidity decreases with the increase in lethal ratio and cell membrane permeability. The viscosity of cell membrane increases with the decrease in fluidity. These phenomena indicated that cell membrane is one of the most key sites during the pulsed electric field treatment, and the increased membrane permeability and the decreased cell membrane fluidity contribute to the cell death.

Experience with Saccharomyces boulardii Probiotic in Oncohaematological Patients.

Science.gov (United States)

Sulik-Tyszka, Beata; Snarski, Emilian; Niedźwiedzka, Magda; Augustyniak, Małgorzata; Myhre, Thorvald Nilsen; Kacprzyk, Anna; Swoboda-Kopeć, Ewa; Roszkowska, Marta; Dwilewicz-Trojaczek, Jadwiga; Jędrzejczak, Wiesław Wiktor; Wróblewska, Marta

2018-06-01

Very few reports have been published to date on the bloodstream infections caused by Saccharomyces spp. in oncohaematological patients, and there are no guidelines on the use of this probiotic microorganism in this population. We describe the use of probiotic preparation containing Saccharomyces boulardii in a large group of oncohaematological patients. We retrospectively analysed the data from 32,000 patient hospitalisations at the haematological centre during 2011-2013 (including 196 haematopoietic stem cell transplant recipients) in a tertiary care university-affiliated hospital. During the study period, 2270 doses of Saccharomyces boulardii probiotic were administered to the oncohaematological patients. In total, 2816 mycological cultures were performed, out of which 772 (27.4%) were positive, with 52 indicating digestive tract colonisation by Saccharomyces spp., mainly in patients with acute myeloid leukaemia (AML), myelodysplastic syndrome (MDS) or multiple myeloma (MM). While colonised, they were hospitalised for 1683 days and 416 microbiological cultures of their clinical samples were performed. In the studied group of patients, there were six blood cultures positive for fungi; however, they comprised Candida species: two C. glabrata, one C. albicans, one C. krusei, one C. tropicalis and one C. parapsilosis. There was no blood culture positive for Saccharomyces spp. Our study indicates that despite colonisation of many oncohaematological patients with Saccharomyces spp., there were no cases of fungal sepsis caused by this species.

Attempt to stimulate cell division in Saccharomyces cerevisiae with weak ultraviolet light

International Nuclear Information System (INIS)

Quickenden, T.I.; Matich, A.J.; Pung, S.H.; Tilbury, R.N.

1989-01-01

Liquid cultures of the yeast Saccharomyces cerevisiae were irradiated with weak light having irradiances ranging from ca. 1 X 10(2) to 5 X 10(9) photons cm-2 s-1 and at wavelengths ranging from 200 to 700 nm. When particular care was taken to control the temperature of the cultures and the flow rate of oxygen, no evidence was obtained for stimulation of either yeast growth or division by the incident light. These results do not support the claims of early workers that very low intensity uv light can stimulate cell division in living organisms

Tolerant industrial yeast Saccharomyces cerevisiae posses a more robust cell wall integrity signaling pathway against 2-furaldehyde and 5-(hydroxymethyl)-2-furaldehyde

Science.gov (United States)

Cell wall integrity signaling pathway in Saccharomyces cerevisiae is a conserved function for detecting and responding to cell stress conditions but less understood for industrial yeast. We dissected gene expression dynamics for a tolerant industrial yeast strain NRRL Y-50049 in response to challeng...

Effect of {sup 60} Co gamma radiation on trehalose level of Saccharomyces boulardii cells; Efeito da radiacao gama {sup 60} Co nos niveis de trealose de celulas de Saccharomyces boulardii

Energy Technology Data Exchange (ETDEWEB)

Santos, Raquel Gouvea dos; Neves, Maria Jose [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil). Nucleo de Radiobiologia; Duarte, Rinaldo; Nicoli, Jacques R. [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Microbiologia

1996-07-01

The medicine Floratil used for diarrhea treatment is composed by lyophilized yeast cells of Saccharomyces boulardii. The action mechanism of this product is unknown. The efficacy of S. boulardii depends on its viability. The increase in the trehalose level in S. cerevisiae cells submitted to a previous sub-lethal level heat shock results in resistance to a lethal shock. The aim of this work was to study weather the cell trehalose level is involved also in the resistance of gamma irradiation. It was noted that the yeast cells surviving to gamma irradiation had more trehalose level than control cells. Apparently there is a positive correlation between of trehalose level and gamma irradiation resistance of S.boulardii cells. (author)

In vitro screening of probiotic properties of Saccharomyces cerevisiae var. boulardii and food-borne Saccharomyces cerevisiae strains

DEFF Research Database (Denmark)

van der Aa Kuhle, Alis; Skovgaard, Kerstin; Jespersen, Lene

2005-01-01

.6-16.8%) recorded for two isolates from blue veined cheeses. Merely 25% of the S. cerevisiae var. boulardii strains displayed good adhesive properties (16.2-28.0%). The expression of the proinflammatory cytokine IL-1α decreased strikingly in IPEC-J2 cells exposed to a Shiga-like toxin 2e producing Escherichia coli...... strain when the cells were pre- and coincubated with S. cerevisiae var. boulardii even though this yeast strain was low adhesive (5.4%), suggesting that adhesion is not a mandatory prerequisite for such a probiotic effect. A strain of S. cerevisiae isolated from West African sorghum beer exerted similar......The probiotic potential of IS Saccharomyces cerevisiae strains used for production of foods or bevel-ages or isolated from such, and eight strains of Saccharomyces cerevisiae var. boulardii, was investigated. All strains included were able to withstand pH 2.5 and 0.3% Ox-all. Adhesion...

Effects of cell entrapment in Ca-alginate on the metabolism of yeast Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Galazzo, J.L.

1989-01-01

Saccharomyces cerevisiae cells grown in suspension have been immobilized in calcium-alginate beads. Fermentation rates and intracellular composition have been determined under nongrowing conditions in these Ca-alginate entrapped cells and for identical cells in suspension. Glucose uptake and ethanol and glycerol production are approximately two times faster in immobilized cells than in suspended cells. Intermediate metabolite levels such as fructose-1,6-diphosphate, glucose-6-phosphate and 3-phosphoglycerate have been determined by phosphorus-31 nuclear magnetic resonance (NMR) spectroscopy under glucose fermenting conditions. Carbon-13 NMR shows an increase in polysaccharide production in immobilized cells. S. cerevisiae cells grown within a Ca-alginate matrix have a specific growth rate 40% lower than the growth rate of similar cells cultivated in suspension. Alginate-grown cells have been used to compare glucose fermentation under nongrowing conditions in suspended and Ca-entrapped cells. Fermentation rate is higher in immobilized cells than in suspended cells. The observed differences in intracellular components between suspended and immobilized cells are qualitatively similar to the differences observed for cells grown in suspension. Ethanol production rate is 2.7 times faster in immobilized alginate-grown cells than in suspended suspension-grown cells

Zymogram profiling of superoxide dismutase and catalase activities allows Saccharomyces and non-Saccharomyces species differentiation and correlates to their fermentation performance.

Science.gov (United States)

Gamero-Sandemetrio, Esther; Gómez-Pastor, Rocío; Matallana, Emilia

2013-05-01

Aerobic organisms have devised several enzymatic and non-enzymatic antioxidant defenses to deal with reactive oxygen species (ROS) produced by cellular metabolism. To combat such stress, cells induce ROS scavenging enzymes such as catalase, peroxidase, superoxide dismutase (SOD) and glutathione reductase. In the present research, we have used a double staining technique of SOD and catalase enzymes in the same polyacrylamide gel to analyze the different antioxidant enzymatic activities and protein isoforms present in Saccharomyces and non-Saccharomyces yeast species. Moreover, we used a technique to differentially detect Sod1p and Sod2p on gel by immersion in NaCN, which specifically inhibits the Sod1p isoform. We observed unique SOD and catalase zymogram profiles for all the analyzed yeasts and we propose this technique as a new approach for Saccharomyces and non-Saccharomyces yeast strains differentiation. In addition, we observed functional correlations between SOD and catalase enzyme activities, accumulation of essential metabolites, such as glutathione and trehalose, and the fermentative performance of different yeasts strains with industrial relevance.

Simultaneous production of buds on mother and daughter cells of Saccharomyces cerevisiae in the presence of hydroxyurea

Energy Technology Data Exchange (ETDEWEB)

Yamada, K; Michio, I

1979-12-01

Individual budding yeast cells, Saccharomyces cerevisiae, enclosed in small culture chambers were observed through two budding cycles to examine their behavior during growth and division. In the nutrient medium (YHG medium), the duration of the budding cycles was 77 minutes for mother cells and 90 minutes for daughter cells. Continuous exposure of cells to 16 or 32 mm hydroxyurea extended the duration of the cycles and increased the volume of cells, resulting in the formation of abnormally large and equal-sized mother-daughter pairs. Each cell of these pairs subsequently produced buds simultaneously. Stained cell nuclei showed simultaneous nuclear division. This synchronous budding on mother-daughter pairs was repeated in the next budding cycle. The coordination of growth with division is discussed in relation to these results.

Microbial cells as biosorbents for heavy metals: accumulation of Uranium by Saccharomyces cerevisiae and Pseudomonas aeruginosa

International Nuclear Information System (INIS)

Strandberg, G.W.; Shumate, S.E. II; Parrott, J.R. Jr.

1981-01-01

Uranium accumulated extracellularly on the surfaces of Saccharomyces cerevisiae cells. The rate and extent of accumulation were subject to environmental parameters, such as pH, temperature, and interference by certain anions and cations. Uranium accumulation by Pseudomonas aeruginosa occurred intracellularly and was extremely rapid (<10 s), and no response to environmental parameters could be detected. Metabolism was not required for metal uptake by either organism. Cell-bound uranium reached a concentration of 10 to 15% of the dry cell weight, but only 32% of the S. cerevisiae cells and 44% of the P. aeruginosa cells within a given population possessed visible uranium deposits when examined by electron microscopy. Rates of uranium uptake by S. cerevisiae were increased by chemical pretreatment of the cells. Uranium could be removed chemically from S. cerevisiae cells, and the cells could then be reused as a biosorbent

Karyotypes of Saccharomyces sensu lato species

DEFF Research Database (Denmark)

Petersen, Randi Føns; Nilsson-Tilgren, Torsten; Piskur, Jure

1999-01-01

An improved pulsed-field electrophoresis program was developed to study differently sized chromosomes within the genus Saccharomyces. The number of chromosomes in the type strains was shown to be nine in Saccharomyces castellii and Saccharomyces dairenensis, 12 in Saccharomyces servazzii...... and Saccharomyces unisporus, 16 in Saccharomyces exiguus and seven in Saccharomyces kluyveri. The sizes of individual chromosomes were resolved and the approximate genome sizes were determined by the addition of individual chromosomes of the karyotypes. Apparently. the genome of S. exiguus, which is the only...... Saccharomyces sensu late yeast to contain small chromosomes, is larger than that of Saccharomyces cerevisiae. On the other hand, other species exhibited genome sizes that were 10-25% smaller than that of S. cerevisiae. Well-defined karyotypes represent the basis for future genome mapping and sequencing projects...

Biotechnology of non-Saccharomyces yeasts--the ascomycetes.

Science.gov (United States)

Johnson, Eric A

2013-01-01

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

Ethanol production from Jerusalem artichoke by strains of Saccharomyces cheresiensis and Saccharomyces beticus

Energy Technology Data Exchange (ETDEWEB)

Pourrat, H.; Barthomeuf, C.; Regerat, F.; Carnat, A.P.; Carnat, A.

1983-03-01

Ethanol production from Jerusalem artichoke which is the most interesting autochtonous material has been studied. Two selected and acclimatised strains of Saccharomyces: Saccharomyces cheresiensis and Saccharomyces beticus were retained. The fermentation conditions, exactly definited, makes it possible to obtain in 4 days a theoric yield.

Influence of α sex factor on the biosynthesis of the cell wall from Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Diaz, S.; Zinker, S.; Ruiz-Herrera, J.

1984-01-01

Cells of Saccharomyces cerevisiae produce peptide hormones (a and α) which dramatically affect the physiology, structure, and behavior of cells from the opposite mating type, presumably in preparation for conjugation. Some cell division cycle mutants mimick several of the changes induced by α factor. Accordingly, conditional mutants cdc 28, cdc 36, cdc 37, and cdc 39 undergo arrest in G1, exhibit shmoo morphology and are able to mate when they are transferred to the restrictive temperature. Formation of shmoo cells would require increased synthesis of glycosyl transferases involved in the biosynthesis of cell wall polysaccharides. Accordingly, the authors investigated the effect of G1 arrest on the chemical composition of the cell wall and on the levels of glycosyl transferases. Arrest in G1 was obtained by two methods: addition of α factor, and transfer of a cdc 28 mutant to the restrictive temperature

Genetic and phenotypic characterization of Saccharomyces spp. strains isolated in distillery plants.

Science.gov (United States)

Úbeda, Juan F; Chacón-Ocaña, Maria; Díaz-Hellín, Patricia; Ramírez-Pérez, Hector; Briones, Ana

2016-06-01

In this study, the biodiversity and some interesting phenotypic properties of Saccharomyces wild yeasts isolated in distilleries, at least 100 years old, located in La Mancha (Spain), were determined. Strains were genetically characterized by RFLP-mtDNA, which confirmed a great genetic biodiversity with 73% of strains with different mtDNA profiles, highlighting the large variability found in sweet and fermented piquette substrata. The predominant species identified was S. cerevisiae, followed by S. paradoxus and S. bayanus Due to the residual sugar-alcohol extraction process using warm water, a great number of thermophilic Saccharomyces strains with a great cell vitality were found to have potential use as starters in distillery plants. Interesting technological properties such as cell vitality and growth rate at different temperatures were studied. The thermal washing process for the extraction of alcohol and reducing sugars of some raw materials contributes to the presence of Saccharomyces strains with technologically interesting properties, especially in terms of vitality and resistance to high temperatures. Due to the fact that fermentation is spontaneous, the yeast biota of these environments, Saccharomyces and non-Saccharomyces, is very varied so these ecological niches are microbial reserves of undoubted biotechnological interest. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Production of Saccharomyces cerevisiae biomass in papaya extract ...

African Journals Online (AJOL)

Extracts of papaya fruit were used as substrate for single cell protein (SCP) production using Saccharomyces cerevisiae. A 500 g of papaya fruit was extracted with different volumes of sterile distilled water. Extraction with 200 mL of sterile distilled water sustained highest cell growth. Biochemical analysis of dry biomass ...

Anti-oxidant effects of pomegranate juice on Saccharomyces cerevisiae cell growth.

Science.gov (United States)

Aslan, Abdullah; Can, Muhammed İsmail; Boydak, Didem

2014-01-01

Pomegranate juice has a number of positive effects on both human and animal subjects. Four groups were used in this study. i: Control group, ii: H2O2 group, iii: Pomegranate juice (PJ) group and iv: PJ + H2O2 group. Following the sterilization method for pomegranate juice (10%) and H2O2 (6% v/v), Saccharomyces cerevisiae cultures were added and the cultivation incubated at 35°C for 72 hours. Fatty acids and vitamin concentrations were measured using HPLC and GC and the total protein bands profile were determined by SDS-PAGE. According to our results statistically significant differences have been determined among the study groups in terms of fatty acids and vitamin (pPomegranate juice increased vitamins, fatty acids and total protein expression in Saccharomyces cerevisiae in comparison with the control. Pomegranate juice has a positive effect on fatty acid, vitamin and protein synthesis by Saccharomyces cerevisiae. Accordingly, we believe that it has significantly decreased oxidative damage thereby making a positive impact on yeast development.

Radiation induced formation of giant cells in Saccharomyces uvarum. Pt. 4. Macromolecular synthesis and protein patterns

Energy Technology Data Exchange (ETDEWEB)

Rink, H; Baumstark-Khan, C; Partke, H J

1986-08-01

X-irradiated (1.0 kGy) yeast cells (Saccharomyces uvarum, ATCC 9080), grown in liquid medium stop their mitotic activities and form giant cells by development of several buds which do not separate from mother cells. Depending on the time in culture, wet and dry weights per cell, protein- RNA- and DNA- contents per cell as well as incorporation rates of /sup 14/C-leucine per cell and per hour and patterns (isoelectric focusing) of water soluble proteins were studied. Weights per cell, RNA and protein contents per cell and /sup 14/C-leucine incorporation rates increase markedly in giant cells, whereas DNA content per cell is only duplicated. Protein patterns in isoelectric focusing show one interesting difference. In samples from giant cells one protein band (IP=6.63) decreases after 8 h in culture and later on disappears completely. This finding is not due to primary damage in X-irradiated DNA but seems to be related to the control of cell cycle events.

THE EFFECT OF BETA GLUCAN OF SACCHAROMYCES CEREVISAE ON THE INCREASE OF THE NUMBER OF BRAIN CELLS IN SUBSTANTIA NIGRA BRAIN OF PARKINSON’S WISTAR STRAIN RAT (RATTUS NORVEGICUS MODEL INDUCED WITH ROTENONE

Directory of Open Access Journals (Sweden)

Masruroh Rahayu

2015-01-01

Full Text Available ackground and aims. One of many neurodegenerative diseases afflicting the elderly is Parkinson. Beta glucan from Saccharomyces cerevisae is very potential to be used as a regenerative therapy of Parkinson's disease. Beta glucan can increase the mobilization of hematopoietic stem cells (HSCs from the bone marrow into the damaged tissues. Hematopoietic stem cells (HSCs which have been mobilized can regenerate and differentiate into brain cells so that the symptoms of Parkinson would be reduced. This research aims to find out the effects of the addition of Saccharomyces cerevisae toward the number of brain cells in substantia nigra Parkinson’s rat model. Method. The research was experimental in vivo using the draft of randomized post test only controlled group design. There were five groups that become the sample in this research with 5 rats for each group, i.e. negative control group, positive control group, Treatment Group 1, 2 and 3 (Rotenone + Saccharomyces cerevisae 18 mg/kgBB, 36 mg/kgBB, 72 mg/kgBBfor 4 weeks. Variable measured in this study was the number of brain cells in substantia nigra. The results of this study showed that Treatment Group 3 (72 mg/kgBB was a group with the largest number of brain cells than the other treatment groups. Statistical data obtained showed that the average number of brain cells in negative control group was 192.00 cells; positive control amounted to 116.80 cells; Treatment 1 amounted to 135.40 cells; Treatment 2 amounted to 140.80 cells; and Treatment 3 amounted to 161.80 cells. Result. The result of ANOVA test showed a significant difference between groups (p< 0.05, while the correlation test result indicated a strong correlation between the dose of Saccharomyces cerevisae and the number of substantia nigra of rat’s brain cells (r = 0,818. Conclusion. From this research, it can be concluded that the addition of Saccharomyces cerevisae with a dose of 18mg/kgBB, 36mg/kgBBdan 72 mg/kgBB is able to increase

Secretory production of cell wall components by Saccharomyces cerevisiae protoplasts in static liquid culture.

Science.gov (United States)

Aoyagi, Hideki; Ishizaka, Mikiko; Tanaka, Hideo

2012-04-01

When protoplasts of Saccharomyces cerevisiae T7 and IFO 0309 are cultured in a static liquid culture at 2.5 × 10(6) protoplasts/ml, cell wall regeneration does not occur and cell wall components (CWC) are released into the culture broth. By using a specialized fluorometer, the concentrations of CWC could be measured on the basis of the fluorescence intensity of the CWC after staining with Fluostain I. The inoculum concentration, pH, and osmotic pressure of the medium were important factors for the production of CWC in culture. Under optimal culture conditions, S. cerevisiae T7 protoplasts produced 0.91 mg/ml CWC after 24 h. The CWC induced the tumor necrosis factor-α production about 1.3 times higher than that of the commercially available β-1,3/1,6-glucan from baker's yeast cells.

A CORN STEM AS BIOMATERIAL FOR SACCHAROMYCES CEREVISIAE CELLS IMMOBILIZATION FOR THE ETHANOL PRODUCTION

Directory of Open Access Journals (Sweden)

Vesna Vučurović

2008-11-01

Full Text Available This study provides a preliminary contribution to the development of a bioprocess for the production of ethanol using Saccharomyces cerevisiae cells immobilized onto a corn stem. For this purpose, the yeast cells were submitted to the batch tests in situ adsorption onto 0.5 cm long corn stem. Cells immobilization was analyzed by optical microscopy. The number of the yeast cells, fermentation kinetics, the ethanol yield in the presence or the absence of the support in the fermentation medium was investigated. It was determined that the addition of the corn stem led to the abrupt increase of the yeast cells number in substrate, ethanol yield, pH value, a total dissolved salts content and substrate conductivity. The addition of 5 and 10g of the corn stem pith per liter of the medium decreased the amount of residual sugar. The results indicate that a corn stem might be a good carrier for the yeast cell immobilization, and also a cheap alternative recourse of mineral components with the possibility of application for improving ethanol productivities.

Ethanol production using Saccharomyces cerevisiae cells immobilised on corn stem ground tissue

Directory of Open Access Journals (Sweden)

Vučurović Vesna M.

2009-01-01

Full Text Available Cell immobilisation in alcoholic fermentation has been extensively studied during the past few decades because of its technical and economical advantages over those of free cell systems. A biocatalyst was prepared by immobilising a commercial Saccharomyces cerevisiae strain (baker yeast on corn stem ground tissue for use in alcoholic fermentation. For this purpose, the yeast cells were submitted to the batch tests 'in situ' adsorption onto pieces of the corn stem ground tissue. Cells immobilisation was analysed by optical microscopy. It was determined that the addition of the corn stem ground tissue led to an increase of the pH value, total dissolved salts content, and sugar content in fermentation medium. The addition of 5 and 10g of the corn stem ground tissue per liter of medium, increased ethanol yield, decreased amount of residual sugar and the cells immobilisation was effective. Corn stem is one of the abundant, available, inexpensive, stable, reusable, nontoxic celulosic biomaterial with high porosity, which facilitates the transmission of substrates and products between carrier and medium. The prepared immobilised biocatalyst showed higher fermentation activity than free cells. The results indicate that corn stem might be an interesting support for yeast cell immobilisation, and also a cheap alternative recourse of mineral components with possibility of application for improving ethanol productivities.

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

Repair of UV-damaged incoming plasmid DNA in Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Keszenman-Pereyra, David

1990-01-01

A whole-cell transformation assay was used for the repair of UV-damaged plasma DNA in highly-transformable haploid strains of Saccharomyces cerevisiae having different repair capabilities. The experiments described demonstrate that three epistasis groups (Friedberg 1988) are involved in the repair of UV-incoming DNA and that the repair processes act less efficiently on incoming DNA than they do on chromosomal DNA. The implications of these findings for UV repair in Saccharomyces cerevisiae are discussed. (author)

Radio protective effects of calcium channel blockers (Deltiazem) on survival of Saccharomyces cerevisiae cells irradiated with different doses of gamma rays

Energy Technology Data Exchange (ETDEWEB)

Alya, G; Shamma, M; Sharabi, N [Atomic Energy Commission, Damascus (Syrian Arab Republic), Dept. of Molecular Biology and Biotechnology

2007-03-15

Investigations of radioprotective effects of Deltiazem (as one of the commonly used calcium channel blockers, which is used in the treatment of acute and chronic angina and spasmo angina, in addition to the treatment of different types of essential hypertension) has been carried on Saccharomyces Cerevisiae cells. Cells cultures of the most famous yeast Saccharomyces Cerevisiae (bakers yeast) were irradiated with different doses of gamma rays. Results revealed that the necessary dose of gamma rays that leads to 10% of survived cellular population (D10 value) was about 256 Gy. This irradiation dose was used then in all irradiation experiments on culture of S. Cerevisiae cells in which different concentrations of Deltiazem (55, 110, 165 mg/Kg medium) were added before and after irradiation in order to study the radio protective effect of Deltiazem. Results showed that Deltiazem enhances survival percentage of irradiated S. Cerevisiae cultures in a concentration dependent manner. This study confirmed our previous works, which had demonstrated that Deltiazem protects lethally and supralethally irradiated rats, and enhances survival of pre-irradiated Deltiazem treated animals.(author)

Radio protective effects of calcium channel blockers (Deltiazem) on survival of Saccharomyces cerevisiae cells irradiated with different doses of gamma rays

International Nuclear Information System (INIS)

Alya, G.; Shamma, M.; Sharabi, N.

2007-03-01

Investigations of radioprotective effects of Deltiazem (as one of the commonly used calcium channel blockers, which is used in the treatment of acute and chronic angina and spasmo angina, in addition to the treatment of different types of essential hypertension) has been carried on Saccharomyces Cerevisiae cells. Cells cultures of the most famous yeast Saccharomyces Cerevisiae (bakers yeast) were irradiated with different doses of gamma rays. Results revealed that the necessary dose of gamma rays that leads to 10% of survived cellular population (D10 value) was about 256 Gy. This irradiation dose was used then in all irradiation experiments on culture of S. Cerevisiae cells in which different concentrations of Deltiazem (55, 110, 165 mg/Kg medium) were added before and after irradiation in order to study the radio protective effect of Deltiazem. Results showed that Deltiazem enhances survival percentage of irradiated S. Cerevisiae cultures in a concentration dependent manner. This study confirmed our previous works, which had demonstrated that Deltiazem protects lethally and supralethally irradiated rats, and enhances survival of pre-irradiated Deltiazem treated animals.(author)

The adsorption of Sr(II) and Cs(I) ions by irradiated Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Yiming Tan; Jundong Feng; Liang Qiu; Zhentian Zhao; Xiaohong Zhang; Haiqian Zhang

2017-01-01

Adsorption behavior and mechanism of Sr(II) and Cs(I) in single and binary solutions using irradiated Saccharomyces cerevisiae was investigated. The effects of several environmental factors on Sr(II) and Cs(I) adsorption to irradiated Saccharomyces cerevisiae was determined. The equilibrium experimental data were simulated by different kinetic models and isotherm models. The combined effect of Sr(II) and Cs(I) on Saccharomyces cerevisiae is generally antagonistic. SEM and EDS analyses indicate that crystals formed on the cell surface are precipitate of Sr(II) and Cs(I), respectively. (author)

Chitinase and chitin synthase 1: counterbalancing activities in cell separation of Saccharomyces cerevisiae.

Science.gov (United States)

Cabib, E; Silverman, S J; Shaw, J A

1992-01-01

Previous results [E. Cabib, A. Sburlati, B. Bowers & S. J. Silverman (1989) Journal of Cell Biology 108, 1665-1672] strongly suggested that the lysis observed in daughter cells of Saccharomyces cerevisiae defective in chitin synthase 1 (Chs1) was caused by a chitinase that partially degrades the chitin septum in the process of cell separation. Consequently, it was proposed that in wild-type cells, Chs1 acts as a repair enzyme by replenishing chitin during cytokinesis. The chitinase requirement for lysis has been confirmed in two different ways: (a) demethylallosamidin, a more powerful chitinase inhibitor than the previously used allosamidin, is also a much better protector against lysis and (b) disruption of the chitinase gene in chs1 cells eliminates lysis. Reintroduction of a normal chitinase gene, by transformation of those cells with a suitable plasmid, restores lysis. The percentage of lysed cells in strains lacking Chs1 was not increased by elevating the chitinase level with high-copy-number plasmids carrying the hydrolase gene. Furthermore, the degree of lysis varied in different chs1 strains; lysis was abolished in chs1 mutants containing the scs1 suppressor. These results indicate that, in addition to chitinase, lysis requires other gene products that may become limiting.

Influence of free radicals generated by gamma irradiation on the trehalose levels in Saccharomyces boulardii leaven cells; Influencia de radicais livres gerados pela irradiacao gama nos niveis de trealose em celulas da levedura Saccharomyces boulardii

Energy Technology Data Exchange (ETDEWEB)

Martins, Flaviano dos Santos; Vianna, Cristina Roscoe [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil). Lab. de Radiobiologia]|[Minas Gerais Univ, Belo Horizonte, MG (Brazil). Dept. de Microbiologia; Neves, Maria Jose [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil). Lab. de Radiobiologia

2002-07-01

Lyophilized cells of yeast Saccharomyces boulardii were submit to the gamma irradiation ({sup 60} Cobalt). It was noted that the yeast cells surviving to gamma irradiation had more trehalose than control cells. The incubation of cells with H{sub 2}0{sub 2} induces the synthesis of trehalose but the exposition to CdCl{sub 2} induces the accumulation of trehalose only in low concentrations. Apparently there is a positive correlation between of trehalose level and gamma irradiation resistance of S. boulardii cells. It was not observed any correlation with the level of trehalose determined and the oxidative stress tested. (author)

Kluyveromyces marxianus and Saccharomyces boulardii induce distinct levels of dendritic cell cytokine secretion and significantly different T cell responses In Vitro

DEFF Research Database (Denmark)

Smith, Ida Mosbech; Baker, Adam; Christensen, Jeffrey E

2016-01-01

induction of a Treg response characterized by robust IL-10 secretion. In addition, we blocked relevant DC surface receptors and investigated the stimulating properties of β-glucan containing yeast cell wall extracts. K. marxianus and S. boulardii induced distinct levels of DC cytokine secretion, primarily...... driven by Dectin-1 recognition of β-glucan components in their cell walls. Upon co-incubation of yeast exposed DCs and naive T cells, S. boulardii induced a potent IFNγ response indicating TH1 mobilization. In contrast, K. marxianus induced a response dominated by Foxp3+ Treg cells, a characteristic...... of the present study was to characterize the immune modulating properties of the food-related yeast Kluyveromyces marxianus in terms of adaptive immune responses indicating inflammation versus tolerance and to explore the mechanisms behind the observed responses. Benchmarking against a Saccharomyces boulardii...

Cell Wall-Related Bionumbers and Bioestimates of Saccharomyces cerevisiae and Candida albicans

Science.gov (United States)

de Koster, Chris G.; Brul, Stanley

2014-01-01

Bionumbers and bioestimates are valuable tools in biological research. Here we focus on cell wall-related bionumbers and bioestimates of the budding yeast Saccharomyces cerevisiae and the polymorphic, pathogenic fungus Candida albicans. We discuss the linear relationship between cell size and cell ploidy, the correlation between cell size and specific growth rate, the effect of turgor pressure on cell size, and the reason why using fixed cells for measuring cellular dimensions can result in serious underestimation of in vivo values. We further consider the evidence that individual buds and hyphae grow linearly and that exponential growth of the population results from regular formation of new daughter cells and regular hyphal branching. Our calculations show that hyphal growth allows C. albicans to cover much larger distances per unit of time than the yeast mode of growth and that this is accompanied by strongly increased surface expansion rates. We therefore predict that the transcript levels of genes involved in wall formation increase during hyphal growth. Interestingly, wall proteins and polysaccharides seem barely, if at all, subject to turnover and replacement. A general lesson is how strongly most bionumbers and bioestimates depend on environmental conditions and genetic background, thus reemphasizing the importance of well-defined and carefully chosen culture conditions and experimental approaches. Finally, we propose that the numbers and estimates described here offer a solid starting point for similar studies of other cell compartments and other yeast species. PMID:24243791

Adaption of Saccharomyces cerevisiae expressing a heterologous protein

DEFF Research Database (Denmark)

Krogh, Astrid Mørkeberg; Beck, Vibe; Højlund Christensen, Lars

2008-01-01

Production of the heterologous protein, bovine aprotinin, in Saccharomyces cerevisiae was shown to affect the metabolism of the host cell to various extent depending on the strain genotype. Strains with different genotypes, industrial and laboroatory, respectively, were investigated. The maximal...

In vitro screening of probiotic properties of Saccharomyces cerevisiae var. boulardii and food-borne Saccharomyces cerevisiae strains.

Science.gov (United States)

van der Aa Kühle, Alis; Skovgaard, Kerstin; Jespersen, Lene

2005-05-01

The probiotic potential of 18 Saccharomyces cerevisiae strains used for production of foods or beverages or isolated from such, and eight strains of Saccharomyces cerevisiae var. boulardii, was investigated. All strains included were able to withstand pH 2.5 and 0.3% Oxgall. Adhesion to the nontumorigenic porcine jejunal epithelial cell line (IPEC-J2) was investigated by incorporation of 3H-methionine into the yeast cells and use of liquid scintillation counting. Only few of the food-borne S. cerevisiae strains exhibited noteworthy adhesiveness with the strongest levels of adhesion (13.6-16.8%) recorded for two isolates from blue veined cheeses. Merely 25% of the S. cerevisiae var. boulardii strains displayed good adhesive properties (16.2-28.0%). The expression of the proinflammatory cytokine IL-1alpha decreased strikingly in IPEC-J2 cells exposed to a Shiga-like toxin 2e producing Escherichia coli strain when the cells were pre- and coincubated with S. cerevisiae var. boulardii even though this yeast strain was low adhesive (5.4%), suggesting that adhesion is not a mandatory prerequisite for such a probiotic effect. A strain of S. cerevisiae isolated from West African sorghum beer exerted similar effects hence indicating that food-borne strains of S. cerevisiae may possess probiotic properties in spite of low adhesiveness.

Metabolic engineering of Saccharomyces cerevisiae: a key cell factory platform for future biorefineries.

Science.gov (United States)

Hong, Kuk-Ki; Nielsen, Jens

2012-08-01

Metabolic engineering is the enabling science of development of efficient cell factories for the production of fuels, chemicals, pharmaceuticals, and food ingredients through microbial fermentations. The yeast Saccharomyces cerevisiae is a key cell factory already used for the production of a wide range of industrial products, and here we review ongoing work, particularly in industry, on using this organism for the production of butanol, which can be used as biofuel, and isoprenoids, which can find a wide range of applications including as pharmaceuticals and as biodiesel. We also look into how engineering of yeast can lead to improved uptake of sugars that are present in biomass hydrolyzates, and hereby allow for utilization of biomass as feedstock in the production of fuels and chemicals employing S. cerevisiae. Finally, we discuss the perspectives of how technologies from systems biology and synthetic biology can be used to advance metabolic engineering of yeast.

Micromechanical and surface adhesive properties of single saccharomyces cerevisiae cells

Science.gov (United States)

Farzi, Bahman; Cetinkaya, Cetin

2017-09-01

The adhesion and mechanical properties of a biological cell (e.g. cell membrane elasticity and adhesiveness) are often strong indicators for the state of its health. Many existing techniques for determining mechanical properties of cells require direct physical contact with a single cell or a group of cells. Physical contact with the cell can trigger complex mechanotransduction mechanisms, leading to cellular responses, and consequently interfering with measurement accuracy. In the current work, based on ultrasonic excitation and interferometric (optical) motion detection, a non-contact method for characterizing the adhesion and mechanical properties of single cells is presented. It is experimentally demonstrated that the rocking (rigid body) motion and internal vibrational resonance frequencies of a single saccharomyces cerevisiae (SC) (baker’s yeast) cell can be acquired with the current approach, and the Young’s modulus and surface tension of the cell membrane as well as surface adhesion energy can be extracted from the values of these acquired resonance frequencies. The detected resonance frequency ranges for single SC cells include a rocking (rigid body) frequency of 330  ±  70 kHz and two breathing resonance frequencies of 1.53  ±  0.12 and 2.02  ±  0.31 MHz. Based on these values, the average work-of-adhesion of SC cells on a silicon substrate in aqueous medium is extracted, for the first time, as WASC-Si=16.2+/- 3.8 mJ {{m}-2} . Similarly, the surface tension and the Young’s modulus of the SC cell wall are predicted as {{σ }SC}=0.16+/- 0.02 N {{m}-1} and {{E}SC}= 9.20  ±  2.80 MPa, respectively. These results are compared to those reported in the literature by utilizing various methods, and good agreements are found. The current approach eliminates the measurement inaccuracies associated with the physical contact. Exciting and detecting cell dynamics at micro-second time-scales is significantly faster than the

Expression of a Dianthus flavonoid glucosyltransferase in Saccharomyces cerevisiae for whole-cell biocatalysis.

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Werner, Sean R; Morgan, John A

2009-07-15

Glycosyltransferases are promising biocatalysts for the synthesis of small molecule glycosides. In this study, Saccharomyces cerevisiae expressing a flavonoid glucosyltransferase (GT) from Dianthus caryophyllus (carnation) was investigated as a whole-cell biocatalyst. Two yeast expression systems were compared using the flavonoid naringenin as a model substrate. Under in vitro conditions, naringenin-7-O-glucoside was formed and a higher specific glucosyl transfer activity was found using a galactose inducible expression system compared to a constitutive expression system. However, S. cerevisiae expressing the GT constitutively was significantly more productive than the galactose inducible system under in vivo conditions. Interestingly, the glycosides were recovered directly from the culture broth and did not accumulate intracellularly. A previously uncharacterized naringenin glycoside formed using the D. caryophyllus GT was identified as naringenin-4'-O-glucoside. It was found that S. cerevisiae cells hydrolyze naringenin-7-O-glucoside during whole-cell biocatalysis, resulting in a low final glycoside titer. When phloretin was added as a substrate to the yeast strain expressing the GT constitutively, the natural product phlorizin was formed. This study demonstrates S. cerevisiae is a promising whole-cell biocatalyst host for the production of valuable glycosides.

Substrate Channelling and Energetics of Saccharomyces cerevisiae ...

African Journals Online (AJOL)

Data collected during the high-cell-density cultivation of Saccharomyces cerevisiae DSM 2155 on glucose in a simulated five-phase feeding strategy of fed-batch process, executed on the Universal BIoprocess CONtrol (UBICON) system using 150L bioreactor over a period of 24h have been analysed. The consistency of the ...

Saccharomyces kudriavzevii and Saccharomyces uvarum differ from Saccharomyces cerevisiae during the production of aroma-active higher alcohols and acetate esters using their amino acidic precursors.

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Stribny, Jiri; Gamero, Amparo; Pérez-Torrado, Roberto; Querol, Amparo

2015-07-16

Higher alcohols and acetate esters are important flavour and aroma components in the food industry. In alcoholic beverages these compounds are produced by yeast during fermentation. Although Saccharomyces cerevisiae is one of the most extensively used species, other species of the Saccharomyces genus have become common in fermentation processes. This study analyses and compares the production of higher alcohols and acetate esters from their amino acidic precursors in three Saccharomyces species: Saccharomyces kudriavzevii, Saccharomyces uvarum and S. cerevisiae. The global volatile compound analysis revealed that S. kudriavzevii produced large amounts of higher alcohols, whereas S. uvarum excelled in the production of acetate esters. Particularly from phenylalanine, S. uvarum produced the largest amounts of 2-phenylethyl acetate, while S. kudriavzevii obtained the greatest 2-phenylethanol formation from this precursor. The present data indicate differences in the amino acid metabolism and subsequent production of flavour-active higher alcohols and acetate esters among the closely related Saccharomyces species. This knowledge will prove useful for developing new enhanced processes in fragrance, flavour, and food industries. Copyright © 2015. Published by Elsevier B.V.

Biocuration at the Saccharomyces genome database.

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Skrzypek, Marek S; Nash, Robert S

2015-08-01

Saccharomyces Genome Database is an online resource dedicated to managing information about the biology and genetics of the model organism, yeast (Saccharomyces cerevisiae). This information is derived primarily from scientific publications through a process of human curation that involves manual extraction of data and their organization into a comprehensive system of knowledge. This system provides a foundation for further analysis of experimental data coming from research on yeast as well as other organisms. In this review we will demonstrate how biocuration and biocurators add a key component, the biological context, to our understanding of how genes, proteins, genomes and cells function and interact. We will explain the role biocurators play in sifting through the wealth of biological data to incorporate and connect key information. We will also discuss the many ways we assist researchers with their various research needs. We hope to convince the reader that manual curation is vital in converting the flood of data into organized and interconnected knowledge, and that biocurators play an essential role in the integration of scientific information into a coherent model of the cell. © 2015 Wiley Periodicals, Inc.

Review of Saccharomyces boulardii as a treatment option in IBD.

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Sivananthan, Kavitha; Petersen, Andreas Munk

2018-05-17

Review of the yeast Saccharomyces boulardii as a treatment option for the inflammatory bowel diseases (IBD) ulcerative colitis and Crohn's disease. IBD is caused by an inappropriate immune response to gut microbiota. Treatment options could therefore be prebiotics, probiotics, antibiotics and/or fecal transplant. In this review, we have looked at the evidence for the yeast S. boulardii as a treatment option. Searches in PubMed and the Cochrane Library with the MeSH words 'Saccharomyces boulardii AND IBD', 'Saccharomyces boulardii AND Inflammatory Bowel Disease', 'Saccharomyces boulardii AND ulcerative colitis' and 'Saccharomyces boulardii AND Crohn's disease' gave total a total of 80 articles. After exclusions because of irrelevance, articles in other languages and some articles that were not available, 16 articles were included in this review. Three of the clinical trials showed a positive effect of S. boulardii in IBD patients (two Crohn's disease, one ulcerative colitis), while there was one trial that didn't prove any effect (Crohn's disease). Included Animal trials and cell assays describes different anti-inflammatory mechanisms of S. boulardii supporting a possible effect when treating IBD patients. The number of studies of S. boulardii as treatment for IBD is limited. Furthermore, the existing trials have small populations and short duration. We do not have enough evidence to prove the effect of S. boulardii in IBD. Saccharomyces boulardii is, however, a plausible treatment option in the future, but more placebo-controlled clinical studies on both patients with ulcerative colitis and Crohn's disease are needed.

Exploring Protein Function Using the Saccharomyces Genome Database.

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Wong, Edith D

2017-01-01

Elucidating the function of individual proteins will help to create a comprehensive picture of cell biology, as well as shed light on human disease mechanisms, possible treatments, and cures. Due to its compact genome, and extensive history of experimentation and annotation, the budding yeast Saccharomyces cerevisiae is an ideal model organism in which to determine protein function. This information can then be leveraged to infer functions of human homologs. Despite the large amount of research and biological data about S. cerevisiae, many proteins' functions remain unknown. Here, we explore ways to use the Saccharomyces Genome Database (SGD; http://www.yeastgenome.org ) to predict the function of proteins and gain insight into their roles in various cellular processes.

Two pathways of DNA double-strand break repair in G1 cells of Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Glazunov, A.V.

1988-01-01

The G1 cells of the diploid yeast Saccharomyces cerevislae are known to be capable of a slow repair of DNA double-strand breaks (DSB) during holding the cells in a non-nutrient medium. In the present paper, it has been shown that S. cerevislae cells γ-irradiated in the G1 phase of cell cycle are capable of fast repair of DNA DSB; this process is completed within 30-40 min of holding the cells in water at 28 deg C. For this reason, the kinetics of DNA DSB repair during holding the cells in a non-nutrient medium are biphasic, i.e., the first, ''fast'' phase is completed within 30-40 min; wheras the second, ''slow'' one, within 48 h. Mutations rad51, rad52, rad54 and rad55 inhibit the fast repair of DNA DSB, whereas mutations rad50, rad53 and rad57 do not practically influence this process. It has been shown that the observed fast and slow repair of DNA DSB in the G1 diploid cells of S, cerevislae are separate pathways of DNA DSB repair in yeast

On cycles in the transcription network of Saccharomyces cerevisiae

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Berman Piotr

2008-01-01

Full Text Available Abstract Background We investigate the cycles in the transcription network of Saccharomyces cerevisiae. Unlike a similar network of Escherichia coli, it contains many cycles. We characterize properties of these cycles and their place in the regulatory mechanism of the cell. Results Almost all cycles in the transcription network of Saccharomyces cerevisiae are contained in a single strongly connected component, which we call LSCC (L for "largest", except for a single cycle of two transcription factors. The fact that LSCC includes almost all cycles is well explained by the properties of a random graph with the same in- and out-degrees of the nodes. Among different physiological conditions, cell cycle has the most significant relationship with LSCC, as the set of 64 transcription interactions that are active in all phases of the cell cycle has overlap of 27 with the interactions of LSCC (of which there are 49. Conversely, if we remove the interactions that are active in all phases of the cell cycle (25% of interactions to transcription factors, the LSCC would have only three nodes and 5 edges, many fewer than expected. This subgraph of the transcription network consists mostly of interactions that are active only in the stress response subnetwork. We also characterize the role of LSCC in the topology of the network. We show that LSCC can be used to define a natural hierarchy in the network and that in every physiological subnetwork LSCC plays a pivotal role. Conclusion Apart from those well-defined conditions, the transcription network of Saccharomyces cerevisiae is devoid of cycles. It was observed that two conditions that were studied and that have no cycles of their own are exogenous: diauxic shift and DNA repair, while cell cycle and sporulation are endogenous. We claim that in a certain sense (slow recovery stress response is endogenous as well.

Real time, in situ observation of the photocatalytic inactivation of Saccharomyces cerevisiae cells

Energy Technology Data Exchange (ETDEWEB)

Zhang, Jingtao [School of Food and Bioengineering, Zhengzhou University of Light Industry, Zhengzhou 450002 (China); Environment Functional Materials Division, Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Wang, Xiaoxin [Environment Functional Materials Division, Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Li, Qi, E-mail: qili@imr.ac.cn [Environment Functional Materials Division, Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Shang, Jian Ku [Environment Functional Materials Division, Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States)

2015-04-01

An in situ microscopy technique was developed to observe in real time the photocatalytic inactivation process of Saccharomyces cerevisiae (S. cerevisiae) cells by palladium-modified nitrogen-doped titanium oxide (TiON/PdO) under visible light illumination. The technique was based on building a photocatalytic micro-reactor on the sample stage of a fluorescence/phase contrast microscopy capable of simultaneously providing the optical excitation to activate the photocatalyst in the micro-reactor and the illumination to acquire phase contrast images of the cells undergoing the photocatalytic inactivation process. Using TiON/PdO as an example, the technique revealed for the first time the vacuolar activities inside S. cerevisiae cells subjected to a visible light photocatalytic inactivation. The vacuoles responded to the photocatalytic attack by the first expansion of the vacuolar volume and then contraction, before the vacuole disappeared and the cell structure collapsed. Consistent with the aggregate behavior observed from the cell culture experiments, the transition in the vacuolar volume provided clear evidence that photocatalytic disinfection of S. cerevisiae cells started with an initiation period in which cells struggled to offset the photocatalytic damage and moved rapidly after the photocatalytic damage overwhelmed the defense mechanisms of the cells against oxidative attack. - Highlights: • Palladium-modified nitrogen-doped titanium oxidephotocatalyst (TiON/PdO) • Effective visible-light photocatalytic disinfection of yeast cells by TiON/PdO • Real time, in situ observation technique was developed for photocatalytic disinfection. • The fluorescence/phase contrast microscope with a photocatalytic micro-reactor • Yeast cell disinfection happened before the cell structure collapsed.

Single-cell adhesion probed in-situ using optical tweezers: A case study with Saccharomyces cerevisiae

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Castelain, Mickaël; Rouxhet, Paul G.; Pignon, Frédéric; Magnin, Albert; Piau, Jean-Michel

2012-06-01

A facile method of using optical trapping to measure cell adhesion forces is presented and applied to the adhesion of Saccharomyces cerevisiae on glass, in contact with solutions of different compositions. Trapping yeast cells with optical tweezers (OT) is not perturbed by cell wall deformation or cell deviation from a spherical shape. The trapping force calibration requires correction not only for the hydrodynamic effect of the neighboring wall but also for spherical aberrations affecting the focal volume and the trap stiffness. Yeast cells trapped for up to 5 h were still able to undergo budding but showed an increase of doubling time. The proportion of adhering cells showed the expected variation according to the solution composition. The detachment force varied in the same way. This observation and the fact that the detachment stress was exerted parallel to the substrate surface point to the role of interactions involving solvated macromolecules. Both the proportion of adhering cells and the removal force showed a distribution which, in our experimental conditions, must be attributed to a heterogeneity of surface properties at the cell level or at the subcellular scale. As compared with magnetic tweezers, atomic force microscopy, and more conventional ways of studying cell adhesion (shear-flow cells), OT present several advantages that are emphasized in this paper.

Removal of Pyrimethanil and Fenhexamid from Saccharomyces cerevisiae Liquid Cultures

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Etjen Bizaj

2011-01-01

Full Text Available The capacity for the removal of pyrimethanil and fenhexamid, two fungicides commonly used for the control of Botrytis cinerea in vineyards, has been evaluated during an alcoholic fermentation process in batch system. Commercial and wild strains of Saccharomyces cerevisiae were used. Batch fermentations were carried out in yeast extract-malt extract medium (YM with 18.0 % (by mass glucose, and the fungicides were added separately at three concentrations: 0.1, 1.0 and 10.0 mg/L. The removal capacity of yeast strains was also examined in stationary phase cultures of Saccharomyces cerevisiae. Stationary assays were performed with yeast biomass harvested from the stationary phase of an anaerobic fermentation process, with separate additions of 0.1, 1.0 and 10.0 mg/L of both fungicides. Removal studies with stationary phase cells were performed with viable and non-viable cells inactivated with sodium azide. This study clearly shows that both Saccharomyces cerevisiae strains were able to remove fenhexamid and pyrimethanil in stationary and fermentative assays. The removal potential is shown to be strain dependent in stationary but not in fermentative assays. However, the removal potential is dependent on the type of fungicide in both stationary and fermentative assays. In stationary phase cultures no significant difference in fungicide removal potential between viable and non-viable cells was observed, indicating that both pesticides were not degraded by metabolically active cells. However, the presence of both pesticides influenced fermentation kinetics and only pyrimethanil at 10.0 mg/L increased the production of volatile acidity of both strains.

Cell wall structure suitable for surface display of proteins in Saccharomyces cerevisiae.

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Matsuoka, Hiroyuki; Hashimoto, Kazuya; Saijo, Aki; Takada, Yuki; Kondo, Akihiko; Ueda, Mitsuyoshi; Ooshima, Hiroshi; Tachibana, Taro; Azuma, Masayuki

2014-02-01

A display system for adding new protein functions to the cell surfaces of microorganisms has been developed, and applications of the system to various fields have been proposed. With the aim of constructing a cell surface environment suitable for protein display in Saccharomyces cerevisiae, the cell surface structures of cell wall mutants were investigated. Four cell wall mutant strains were selected by analyses using a GFP display system via a GPI anchor. β-Glucosidase and endoglucanase II were displayed on the cell surface in the four mutants, and their activities were evaluated. mnn2 deletion strain exhibited the highest activity for both the enzymes. In particular, endoglucanase II activity using carboxymethylcellulose as a substrate in the mutant strain was 1.9-fold higher than that of the wild-type strain. In addition, the activity of endoglucanase II released from the mnn2 deletion strain by Zymolyase 20T treatment was higher than that from the wild-type strain. The results of green fluorescent protein (GFP) and endoglucanase displays suggest that the amounts of enzyme displayed on the cell surface were increased by the mnn2 deletion. The enzyme activity of the mnn2 deletion strain was compared with that of the wild-type strain. The relative value (mnn2 deletion mutant/wild-type strain) of endoglucanase II activity using carboxymethylcellulose as a substrate was higher than that of β-glucosidase activity using p-nitrophenyl-β-glucopyranoside as a substrate, suggesting that the cell surface environment of the mnn2 deletion strain facilitates the binding of high-molecular-weight substrates to the active sites of the displayed enzymes. Copyright © 2014 John Wiley & Sons, Ltd.

Therapeutic activity of a Saccharomyces cerevisiae-based probiotic and inactivated whole yeast on vaginal candidiasis.

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Pericolini, Eva; Gabrielli, Elena; Ballet, Nathalie; Sabbatini, Samuele; Roselletti, Elena; Cayzeele Decherf, Amélie; Pélerin, Fanny; Luciano, Eugenio; Perito, Stefano; Jüsten, Peter; Vecchiarelli, Anna

2017-01-02

Vulvovaginal candidiasis is the most prevalent vaginal infection worldwide and Candida albicans is its major agent. Vulvovaginal candidiasis is characterized by disruption of the vaginal microbiota composition, as happens following large spectrum antibiotic usage. Recent studies support the effectiveness of oral and local probiotic treatment for prevention of recurrent vulvovaginal candidiasis. Saccharomyces cerevisiae is a safe yeast used as, or for, the production of ingredients for human nutrition and health. Here, we demonstrate that vaginal administration of probiotic Saccharomyces cerevisiae live yeast (GI) and, in part, inactivated whole yeast Saccharomyces cerevisiae (IY), used as post-challenge therapeutics, was able to positively influence the course of vaginal candidiasis by accelerating the clearance of the fungus. This effect was likely due to multiple interactions of Saccharomyces cerevisiae with Candida albicans. Both live and inactivated yeasts induced coaggregation of Candida and consequently inhibited its adherence to epithelial cells. However, only the probiotic yeast was able to suppress some major virulence factors of Candida albicans such as the ability to switch from yeast to mycelial form and the capacity to express several aspartyl proteases. The effectiveness of live yeast was higher than that of inactivated whole yeast suggesting that the synergy between mechanical effects and biological effects were dominant over purely mechanical effects. The protection of epithelial cells to Candida-induced damage was also observed. Overall, our data show for the first time that Saccharomyces cerevisiae-based ingredients, particularly the living cells, can exert beneficial therapeutic effects on a widespread vaginal mucosal infection.

The resistance of the yeast Saccharomyces cerevisiae to the biocide polyhexamethylene biguanide: involvement of cell wall integrity pathway and emerging role for YAP1

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de Morais Marcos A

2011-08-01

Full Text Available Abstract Background Polyhexamethylene biguanide (PHMB is an antiseptic polymer that is mainly used for cleaning hospitals and pools and combating Acantamoeba infection. Its fungicide activity was recently shown by its lethal effect on yeasts that contaminate the industrial ethanol process, and on the PE-2 strain of Saccharomyces cerevisiae, one of the main fermenting yeasts in Brazil. This pointed to the need to know the molecular mechanism that lay behind the cell resistance to this compound. In this study, we examined the factors involved in PHMB-cell interaction and the mechanisms that respond to the damage caused by this interaction. To achieve this, two research strategies were employed: the expression of some genes by RT-qPCR and the analysis of mutant strains. Results Cell Wall integrity (CWI genes were induced in the PHMB-resistant Saccharomyces cerevisiae strain JP-1, although they are poorly expressed in the PHMB-sensitive Saccharomyces cerevisiae PE2 strain. This suggested that PHMB damages the glucan structure on the yeast cell wall. It was also confirmed by the observed sensitivity of the yeast deletion strains, Δslg1, Δrom2, Δmkk2, Δslt2, Δknr4, Δswi4 and Δswi4, which showed that the protein kinase C (PKC regulatory mechanism is involved in the response and resistance to PHMB. The sensitivity of the Δhog1 mutant was also observed. Furthermore, the cytotoxicity assay and gene expression analysis showed that the part played by YAP1 and CTT1 genes in cell resistance to PHMB is unrelated to oxidative stress response. Thus, we suggested that Yap1p can play a role in cell wall maintenance by controlling the expression of the CWI genes. Conclusion The PHMB treatment of the yeast cells activates the PKC1/Slt2 (CWI pathway. In addition, it is suggested that HOG1 and YAP1 can play a role in the regulation of CWI genes.

Saccharomyces boulardii improves humoral immune response to DNA vaccines against leptospirosis.

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Silveira, Marcelle Moura; Conceição, Fabricio Rochedo; Mendonça, Marcelo; Moreira, Gustavo Marçal Schmidt Garcia; Da Cunha, Carlos Eduardo Pouey; Conrad, Neida Lucia; Oliveira, Patrícia Diaz de; Hartwig, Daiane Drawanz; De Leon, Priscila Marques Moura; Moreira, Ângela Nunes

2017-02-01

Saccharomyces boulardii may improve the immune response by enhancing the production of anti-inflammatory cytokines, T-cell proliferation and dendritic cell activation. The immunomodulator effect of this probiotic has never been tested with DNA vaccines, which frequently induce low antibody titers. This study evaluated the capacity of Saccharomyces boulardii to improve the humoral and cellular immune responses using DNA vaccines coding for the leptospiral protein fragments LigAni and LigBrep. BALB/c mice were fed with rodent-specific feed containing 108 c.f.u. of Saccharomycesboulardii per gram. Animals were immunized three times intramuscularly with 100 µg of pTARGET plasmids containing the coding sequences for the above mentioned proteins. Antibody titers were measured by indirect ELISA. Expression levels of IL-4, IL-10, IL-12, IL-17, IFN-γ and TGF-β were determined by quantitative real-time PCR from RNA extracted from whole blood, after an intraperitoneal boost with 50 µg of the recombinant proteins.Results/Key findings. Antibody titers increased significantly after the second and third application when pTARGET/ligAni and pTARGET/ligBrep were used to vaccinate the animals in comparison with the control group (PSaccharomyces boulardii. The results suggested that Saccharomyces boulardii has an immunomodulator effect in DNA vaccines, mainly by stimulating the humoral response, which is often limited in this kind of vaccine. Therefore, the use of Saccharomyces boulardii as immunomodulator represents a new alternative strategy for more efficient DNA vaccination.

Acrolein-Induced Oxidative Stress and Cell Death Exhibiting Features of Apoptosis in the Yeast Saccharomyces cerevisiae Deficient in SOD1.

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Kwolek-Mirek, Magdalena; Zadrąg-Tęcza, Renata; Bednarska, Sabina; Bartosz, Grzegorz

2015-04-01

The yeast Saccharomyces cerevisiae is a useful eukaryotic model to study the toxicity of acrolein, an important environmental toxin and endogenous product of lipid peroxidation. The study was aimed at elucidation of the cytotoxic effect of acrolein on the yeast deficient in SOD1, Cu, Zn-superoxide dismutase which is hypersensitive to aldehydes. Acrolein generated within the cell from its precursor allyl alcohol caused growth arrest and cell death of the yeast cells. The growth inhibition involved an increase in production of reactive oxygen species and high level of protein carbonylation. DNA condensation and fragmentation, exposition of phosphatidylserine at the cell surface as well as decreased dynamic of actin microfilaments and mitochondria disintegration point to the induction of apoptotic-type cell death besides necrotic cell death.

Permeabilization of Saccharomyces fragilis IZ 275 cells with ethanol to obtain a biocatalyst with lactose hydrolysis capacity

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Luiz Rodrigo Ito Morioka

2016-10-01

Full Text Available The permeabilization was used to transform microorganisms in cell biocatalysts with high enzymatic activity. The Saccharomyces fragilis IZ 275 yeast cells were permeabilized with ethanol, as permeabilizing agent. To optimize the permeabilization conditions were used the design of Box-Behnken 15 trials (3 central points. The independent variables and their levels were ethanol (29, 32 and 35%, temperature (15, 20 and 25°C and time (15, 20 and 25 min. The answer (Y function has beta-galactosidase activity (U mg-1. The optimum conditions for obtaining a high enzymatic activity were observed in 35% ethanol concentration, temperature 15ºC and 20 min. treatment time. The maximum activity of the enzyme beta-galactosidase obtained was 10.59 U mg-1. The permeabilization of the S. fragilis IZ 275 cells was efficient.

Ethanol fermentation of molasses by Saccharomyces cerevisiae cells immobilized onto sugar beet pulp

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Vučurović Vesna M.

2012-01-01

Full Text Available Natural adhesion of Saccharomyces cerevisiae onto sugar beet pulp (SBP is a very simple and cheap immobilization method for retaining high cells density in the ethanol fermentation system. In the present study, yeast cells were immobilized by adhesion onto SBP suspended in the synthetic culture media under different conditions such as: glucose concentration (100, 120 and 150 g/l, inoculum concentration (5, 10 and 15 g/l dry mass and temperature (25, 30, 35 and 40°C. In order to estimate the optimal immobilization conditions the yeast cells retention (R, after each immobilization experiment was analyzed. The highest R value of 0.486 g dry mass yeast /g dry mass SBP was obtained at 30°C, glucose concentration of 150 g/l, and inoculum concentration of 15 g/l. The yeast immobilized under these conditions was used for ethanol fermentation of sugar beet molasses containing 150.2 g/l of reducing sugar. Efficient ethanol fermentation (ethanol concentration of 70.57 g/l, fermentation efficiency 93.98% of sugar beet molasses was achieved using S. cerevisiae immobilized by natural adhesion on SBP. [Projekat Ministarstva nauke Republike Srbije, br. TR-31002

Effect of spermidine on the survival of saccharomyces cerevisiae cells irradiated with different doses of gamma rays

International Nuclear Information System (INIS)

Shamma, M.; Alya, G.; Sharabi, N.; Azroony, R.

2005-01-01

Saccharomyces cerevisiae cells were used to test the radioprotective effect of added spermidine [H 3 N(CH 2 ) 3 NH 2 (CH 2 ) 4 NH 3 ] 3+ . Spermidine plays an important role in suppressing radiation damages at certain concentration (10 -5 mol.l -1 ), either via scavenging free radicals or via the frequency of radiation-induced mutations. Spermidine increased noticeably the D 10 value at concentration of 10 -5 mol.l -1 Applying spermidine prior to irradiation was more effective than applying it post irradiation. (author)

Microencapsulation of Saccharomyces cerevisiae and its evaluation to protect in simulated gastric conditions.

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Ghorbani-Choboghlo, Hassan; Zahraei-Salehi, Taghi; Ashrafi-Helan, Javad; Yahyaraeyat, Ramak; Pourjafar, Hadi; Nikaein, Donya; Balal, Asad; Khosravi, Ali-Reza

2015-12-01

Probiotic yeasts are used in production of functional foods and pharmaceutical products. They play an important role in promoting and maintaining human health. Until now, little work has been published on improving the survival of Saccharomyces in stimulated gastrointestinal condition. In this study the exposure of the yeast in the capsulate and free forms to artificial gastrointestinal conditions was assessed and the number of viable Saccharomyces cerevisiae cells during 0 to 120 mines in these conditions was evaluated by a pour plate method using sabouraud dextrose agar. Results showed the shape of the beads was generally spherical, sometimes elliptical with a mean diameter of about 50-90 μm. Also count of viable probiotic cells obtained for all the microcapsules were above the recommended levels for a probiotic food. Also decrease of approximately 4 logs was noted in the number of free cells after 2 h of incubation at pH 2 and 8, when compared to decreases of about 2 logs in the all microencapsulated S. cerevisiae under similar conditions. It is concluded that microencapsulation process was significantly able to increase the survival rate of Saccharomyces in a simulated gastrointestinal condition (p<0.05)..

Genetic Basis for Saccharomyces cerevisiae Biofilm in Liquid Medium

DEFF Research Database (Denmark)

Andersen, Kaj Scherz; Bojsen, Rasmus Kenneth; Gro Rejkjær Sørensen, Laura

2014-01-01

than free-living cells. We investigated the genetic basis for yeast, Saccharomyces cerevisiae, biofilm on solid surfaces in liquid medium by screening a comprehensive deletion mutant collection in the S1278b background and found 71 genes that were essential for biofilm development. Quantitative...

Quality control of fifteen probiotic products containing Saccharomyces boulardii.

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Vanhee, L M E; Goemé, F; Nelis, H J; Coenye, T

2010-11-01

The yeast Saccharomyces boulardii is used as a probiotic for the prevention and treatment of diarrhoea. In this study, the quality of 15 probiotic products containing S. boulardii was verified. Using microsatellite typing, the identity of all Saccharomyces strains in the products was confirmed as S. boulardii. Additionally, solid-phase cytometry (SPC) and a plate method were used to enumerate S. boulardii cells. SPC was not only able to produce results more rapidly than plating (4h compared to 48h) but the cell counts obtained with SPC were significantly higher than the plate counts. Finally, we found that boulardii cells survived 120min in gastric conditions and storage for 3months at 40°C with 75% relative humidity. We developed a SPC method for the quantification of viable S. boulardii cells in probiotics. Additionally, we demonstrated that gastric conditions and storage have a marked effect on the viability of the yeast cells.   To our knowledge, this is the first time SPC is used for the quality control of probiotics with S. boulardii. Additionally, we demonstrated the need for gastric protection and accurate storage. © 2010 The Authors. Journal of Applied Microbiology © 2010 The Society for Applied Microbiology.

Nucleotide-excision repair of DNA in cell-free extracts of the yeast Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Wang, Z.; Wu, X.; Friedberg, E.C.

1993-01-01

A wide spectrum of DNA lesions are repaired by the nucleotide-excision repair (NER) pathway in both eukaryotic and prokaryotic cells. We have developed a cell-free system in Saccharomyces cerevisiae that supports NER. NER was monitored by measuring repair synthesis in DNA treated with cisplatin or with UV radiation. Repair synthesis in vitro was defective in extracts of rad1, rad2, and rad10 mutant cells, all of which have mutations in genes whose products are known to be required for NER in vivo. Additionally, repair synthesis was complemented by mixing different mutant extracts, or by adding purified Rad1 or Rad10 protein to rad1 or rad10 mutant extracts, respectively. The latter observation demonstrates that the Rad1 and Rad10 proteins directly participate in the biochemical pathway of NER. NER supported by nuclear extracts requires ATP and Mg 2+ and is stimulated by polyethylene glycol and by small amounts of whole cell extract containing overexpressed Rad2 protein. The nuclear extracts also contain base-excision repair activity that is present at wild-type levels in rad mutant extracts. This cell-free system is expected to facilitate studies on the biochemical pathway of NER in S. cerevisiae

Cell-autonomous mechanisms of chronological aging in the yeast Saccharomyces cerevisiae

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Anthony Arlia-Ciommo

2014-05-01

Full Text Available A body of evidence supports the view that the signaling pathways governing cellular aging – as well as mechanisms of their modulation by longevity-extending genetic, dietary and pharmacological interventions - are conserved across species. The scope of this review is to critically analyze recent advances in our understanding of cell-autonomous mechanisms of chronological aging in the budding yeast Saccharomyces cerevisiae. Based on our analysis, we propose a concept of a biomolecular network underlying the chronology of cellular aging in yeast. The concept posits that such network progresses through a series of lifespan checkpoints. At each of these checkpoints, the intracellular concentrations of some key intermediates and products of certain metabolic pathways - as well as the rates of coordinated flow of such metabolites within an intricate network of intercompartmental communications - are monitored by some checkpoint-specific ′′master regulator′′ proteins. The concept envisions that a synergistic action of these master regulator proteins at certain early-life and late-life checkpoints modulates the rates and efficiencies of progression of such processes as cell metabolism, growth, proliferation, stress resistance, macromolecular homeostasis, survival and death. The concept predicts that, by modulating these vital cellular processes throughout lifespan (i.e., prior to an arrest of cell growth and division, and following such arrest, the checkpoint-specific master regulator proteins orchestrate the development and maintenance of a pro- or anti-aging cellular pattern and, thus, define longevity of chronologically aging yeast.

Cell-autonomous mechanisms of chronological aging in the yeast Saccharomyces cerevisiae.

Science.gov (United States)

Arlia-Ciommo, Anthony; Leonov, Anna; Piano, Amanda; Svistkova, Veronika; Titorenko, Vladimir I

2014-05-27

A body of evidence supports the view that the signaling pathways governing cellular aging - as well as mechanisms of their modulation by longevity-extending genetic, dietary and pharmacological interventions - are conserved across species. The scope of this review is to critically analyze recent advances in our understanding of cell-autonomous mechanisms of chronological aging in the budding yeast Saccharomyces cerevisiae . Based on our analysis, we propose a concept of a biomolecular network underlying the chronology of cellular aging in yeast. The concept posits that such network progresses through a series of lifespan checkpoints. At each of these checkpoints, the intracellular concentrations of some key intermediates and products of certain metabolic pathways - as well as the rates of coordinated flow of such metabolites within an intricate network of intercompartmental communications - are monitored by some checkpoint-specific "master regulator" proteins. The concept envisions that a synergistic action of these master regulator proteins at certain early-life and late-life checkpoints modulates the rates and efficiencies of progression of such processes as cell metabolism, growth, proliferation, stress resistance, macromolecular homeostasis, survival and death. The concept predicts that, by modulating these vital cellular processes throughout lifespan (i.e., prior to an arrest of cell growth and division, and following such arrest), the checkpoint-specific master regulator proteins orchestrate the development and maintenance of a pro- or anti-aging cellular pattern and, thus, define longevity of chronologically aging yeast.

Beneficial properties of probiotic yeast Saccharomyces boulardii

Directory of Open Access Journals (Sweden)

Tomičić Zorica M.

2016-01-01

Full Text Available Saccharomyces boulardii is unique probiotic and biotherapeutic yeast, known to survive in gastric acidity and it is not adversely affected or inhibited by antibiotics or does not alter or adversely affect the normal microbiota. S. boulardii has been utilized worldwide as a probiotic supplement to support gastrointestinal health. The multiple mechanisms of action of S. boulardii and its properties may explain its efficacy and beneficial effects in acute and chronic gastrointestinal diseases that have been confirmed by clinical trials. Caution should be taken in patients with risk factors for adverse events. Its potential application in various dairy foods could offer an alternative probiotic product to people suffering from antibiotic-associated diarrhea. This review discusses the evidence for efficacy and safety of S. boulardii as a probiotic for the prevention and therapy of gastrointestinal disorders in humans.

iTRAQ-based proteome profiling of Saccharomyces cerevisiae and cryotolerant species Saccharomyces uvarum and Saccharomyces kudriavzevii during low-temperature wine fermentation.

Science.gov (United States)

García-Ríos, Estéfani; Querol, Amparo; Guillamón, José Manuel

2016-09-02

Temperature is one of the most important parameters to affect the duration and rate of alcoholic fermentation and final wine quality. Some species of the Saccharomyces genus have shown better adaptation at low temperature than Saccharomyces cerevisiae, which was the case of cryotolerant yeasts Saccharomyces uvarum and Saccharomyces kudriavzevii. In an attempt to detect inter-specific metabolic differences, we characterized the proteomic landscape of these cryotolerant species grown at 12°C and 28°C, which we compared with the proteome of S. cerevisiae (poorly adapted at low temperature). Our results showed that the main differences among the proteomic profiling of the three Saccharomyces strains grown at 12°C and 28°C lay in translation, glycolysis and amino acid metabolism. Our data corroborate previous transcriptomic results, which suggest that S. kudriavzevii is better adapted to grow at low temperature as a result of enhanced more efficient translation. Fitter amino acid biosynthetic pathways can also be mechanisms that better explain biomass yield in cryotolerant strains. Yet even at low temperature, S. cerevisiae is the most fermentative competitive species. A higher concentration of glycolytic and alcoholic fermentation enzymes in the S. cerevisiae strain might explain such greater fermentation activity. Temperature is one of the main relevant environmental variables that microorganisms have to cope with and it is also a key factor in some industrial processes that involve microorganisms. However, we are still far from understanding the molecular and physiological mechanisms of adaptation at low temperatures. The results obtained in this study provided a global atlas of the proteome changes triggered by temperature in three different species of the genus Saccharomyces with different degree of cryotolerance. These results would facilitate a better understanding of mechanisms for how yeast could adapt at the low temperature of growth. Copyright © 2016

Ethanol production by fermentation using immobilized cells of Saccharomyces cerevisiae in cashew apple bagasse.

Science.gov (United States)

Pacheco, Alexandre Monteiro; Gondim, Diego Romão; Gonçalves, Luciana Rocha Barros

2010-05-01

In this work, cashew apple bagasse (CAB) was used for Saccharomyces cerevisiae immobilization. The support was prepared through a treatment with a solution of 3% HCl, and delignification with 2% NaOH was also conducted. Optical micrographs showed that high populations of yeast cells adhered to pre-treated CAB surface. Ten consecutive fermentations of cashew apple juice for ethanol production were carried out using immobilized yeasts. High ethanol productivity was observed from the third fermentation assay until the tenth fermentation. Ethanol concentrations (about 19.82-37.83 g L(-1) in average value) and ethanol productivities (about 3.30-6.31 g L(-1) h(-1)) were high and stable, and residual sugar concentrations were low in almost all fermentations (around 3.00 g L(-1)) with conversions ranging from 44.80% to 96.50%, showing efficiency (85.30-98.52%) and operational stability of the biocatalyst for ethanol fermentation. Results showed that cashew apple bagasse is an efficient support for cell immobilization aiming at ethanol production.

Role of glutathione metabolism status in the definition of some cellular parameters and oxidative stress tolerance of Saccharomyces cerevisiae cells growing as biofilms.

Science.gov (United States)

Gales, Grégoire; Penninckx, Michel; Block, Jean-Claude; Leroy, Pierre

2008-08-01

The resistance of Saccharomyces cerevisiae to oxidative stress (H(2)O(2) and Cd(2+)) was compared in biofilms and planktonic cells, with the help of yeast mutants deleted of genes related to glutathione metabolism and oxidative stress. Biofilm-forming cells were found predominantly in the G1 stage of the cell cycle. This might explain their higher tolerance to oxidative stress and the young replicative age of these cells in an old culture. The reduced glutathione status of S. cerevisiae was affected by the growth phase and apparently plays an important role in oxidative stress tolerance in cells growing as a biofilm.

Evolutionary engineering of Saccharomyces cerevisiae for efficient aerobic xylose consumption

DEFF Research Database (Denmark)

Scalcinati, Gionata; Otero, José Manuel; Van Vleet, Jennifer R. H.

2012-01-01

Industrial biotechnology aims to develop robust microbial cell factories, such as Saccharomyces cerevisiae, to produce an array of added value chemicals presently dominated by petrochemical processes. Xylose is the second most abundant monosaccharide after glucose and the most prevalent pentose s...

Enzymatic activities produced by mixed Saccharomyces and non-Saccharomyces cultures: relationship with wine volatile composition.

Science.gov (United States)

Maturano, Yolanda Paola; Assof, Mariela; Fabani, María Paula; Nally, María Cristina; Jofré, Viviana; Rodríguez Assaf, Leticia Anahí; Toro, María Eugenia; Castellanos de Figueroa, Lucía Inés; Vazquez, Fabio

2015-11-01

During certain wine fermentation processes, yeasts, and mainly non-Saccharomyces strains, produce and secrete enzymes such as β-glucosidases, proteases, pectinases, xylanases and amylases. The effects of enzyme activity on the aromatic quality of wines during grape juice fermentation, using different co-inoculation strategies of non-Saccharomyces and Saccharomyces cerevisiae yeasts, were assessed in the current study. Three strains with appropriate enological performance and high enzymatic activities, BSc562 (S. cerevisiae), BDv566 (Debaryomyces vanrijiae) and BCs403 (Candida sake), were assayed in pure and mixed Saccharomyces/non-Saccharomyces cultures. β-Glucosidase, pectinase, protease, xylanase and amylase activities were quantified during fermentations. The aromatic profile of pure and mixed cultures was determined at the end of each fermentation. In mixed cultures, non-Saccharomyces species were detected until day 4-5 of the fermentation process, and highest populations were observed in MSD2 (10% S. cerevisiae/90% D. vanrijiae) and MSC1 (1% S. cerevisiae/99% C. sake). According to correlation and multivariate analysis, MSD2 presented the highest concentrations of terpenes and higher alcohols which were associated with pectinase, amylase and xylanase activities. On the other hand, MSC1 high levels of β-glucosidase, proteolytic and xylanolytic activities were correlated to esters and fatty acids. Our study contributes to a better understanding of the effect of enzymatic activities by yeasts on compound transformations that occur during wine fermentation.

Survival of Saccharomyces cerevisiae after treatment with the restriction endonuclease Alu I

International Nuclear Information System (INIS)

Winckler, K.; Bach, B.; Obe, G.

1988-01-01

Treatment of yeast cells proficient in the repair of radiation damage (Saccharomyces cervisiae) with the restriction endonuclease Alu I leads to a positive dose-effect relationship between inactivation level and enzyme concentration. The data suggest an uptake of the active restriction enzyme into the cells and a relationship between induction of DNA double-strand breaks and cell killing. (author)

Cornual pregnancy in a patient suffering from sickle cell anemia

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Onilda Labrada Silva

2015-10-01

Full Text Available Nowadays, ectopic pregnancy is a pathological entity of great incidence, which is increased, among other things, by each time earlier sexual relations. Cornual pregnancy is as a result of the implantation of the blastocyte within the segment of the fallopian tube that goes into the uterus wall or between the tubal ostium and the proximal portion of the isthmus. This is a case of a cornual pregnancy in which the use of ultrasonography played an essential role for its diagnosis, since it is about a patient suffering from sickle cell anemia, where it was not possible to clinically eliminate the possibility of an occlusive vessel crisis as the cause of abdominal pain. Subtotal hysterectomy of the right tube was performed. The patient’s evolution is satisfactory.

S-Adenosyl-L-methionine protects the probiotic yeast, Saccharomyces boulardii, from acid-induced cell death.

Science.gov (United States)

Cascio, Vincent; Gittings, Daniel; Merloni, Kristen; Hurton, Matthew; Laprade, David; Austriaco, Nicanor

2013-02-13

Saccharomyces boulardii is a probiotic yeast routinely used to prevent and to treat gastrointestinal disorders, including the antibiotic-associated diarrhea caused by Clostridium difficile infections. However, only 1-3% of the yeast administered orally is recovered alive in the feces suggesting that this yeast is unable to survive the acidic environment of the gastrointestinal tract. We provide evidence that suggests that S. boulardii undergoes programmed cell death (PCD) in acidic environments, which is accompanied by the generation of reactive oxygen species and the appearance of caspase-like activity. To better understand the mechanism of cell death at the molecular level, we generated microarray gene expression profiles of S. boulardii cells cultured in an acidic environment. Significantly, functional annotation revealed that the up-regulated genes were significantly over-represented in cell death pathways Finally, we show that S-adenosyl-L-methionine (AdoMet), a commercially available, FDA-approved dietary supplement, enhances the viability of S. boulardii in acidic environments, most likely by preventing programmed cell death. In toto, given the observation that many of the proven health benefits of S. boulardii are dependent on cell viability, our data suggests that taking S. boulardii and AdoMet together may be a more effective treatment for gastrointestinal disorders than taking the probiotic yeast alone.

Effects of fermentation by Saccharomyces cerevisiae and ...

African Journals Online (AJOL)

yassine

2013-02-13

Feb 13, 2013 ... Effect of Saccharomyces cerevisiae fermentation on the ... beetroot, fermentation, Saccharomyces cerevisiae, betalain compounds. ... by Saccharomyces cerevisiae strains (González et al., .... Both red and yellow pigments were influenced during S. .... in beverages such as white wine, grape fruit, and green.

Saccharomyces cerevisiae has distinct adaptive responses to both hydrogen peroxide and menadione.

OpenAIRE

Jamieson, D J

1992-01-01

Treatment of Saccharomyces cerevisiae cells with low concentrations of either hydrogen peroxide or menadione (a superoxide-generating agent) induces adaptive responses which protect cells from the lethal effects of subsequent challenge with higher concentrations of these oxidants. Pretreatment with menadione is protective against cell killing by hydrogen peroxide; however, pretreatment with hydrogen peroxide is unable to protect cells from subsequent challenge with menadione. This suggests th...

Saccharomyces boulardii inhibits lipopolysaccharide-induced activation of human dendritic cells and T cell proliferation

Science.gov (United States)

Thomas, S; Przesdzing, I; Metzke, D; Schmitz, J; Radbruch, A; Baumgart, D C

2009-01-01

Saccharomyces boulardii (Sb) is a probiotic yeast preparation that has demonstrated efficacy in inflammatory and infectious disorders of the gastrointestinal tract in controlled clinical trials. Although patients clearly benefit from treatment with Sb, little is known on how Sb unfolds its anti-inflammatory properties in humans. Dendritic cells (DC) balance tolerance and immunity and are involved critically in the control of T cell activation. Thus, they are believed to have a pivotal role in the initiation and perpetuation of chronic inflammatory disorders, not only in the gut. We therefore decided to investigate if Sb modulates DC function. Culture of primary (native, non-monocyte-derived) human myeloid CD1c+CD11c+CD123– DC (mDC) in the presence of Sb culture supernatant (active component molecular weight < 3 kDa, as evaluated by membrane partition chromatography) reduced significantly expression of the co-stimulatory molecules CD40 and CD80 (P < 0·01) and the DC mobilization marker CC-chemokine receptor CCR7 (CD197) (P < 0·001) induced by the prototypical microbial antigen lipopolysaccharide (LPS). Moreover, secretion of key proinflammatory cytokines such as tumour necrosis factor-α and interleukin (IL)-6 were notably reduced, while the secretion of anti-inflammatory IL-10 increased. Finally, Sb supernatant inhibited the proliferation of naive T cells in a mixed lymphocyte reaction with mDC. In summary, our data suggest that Sb may exhibit part of its anti-inflammatory potential through modulation of DC phenotype, function and migration by inhibition of their immune response to bacterial microbial surrogate antigens such as LPS. PMID:19161443

Data on dynamic study of cytoophidia in Saccharomyces cerevisiae

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Hui Li

2016-09-01

Full Text Available The data in this paper are related to the research article entitled “Filamentation of metabolic enzymes in Saccharomyces cerevisiae” Q.J. Shen et al. (2016 [1]. Cytoophidia are filamentous structures discovered in fruit flies (doi:10.1016/S1673-8527(0960046-1 J.L. Liu (2010 [2], bacteria (doi:10.1038/ncb2087 M. Ingerson-Mahar et al. (2010 [3], yeast (doi:10.1083/jcb.201003001; doi:10.1242/bio.20149613 C. Noree et al. (2010 and J. Zhang, L. Hulme, J.L. Liu (2014 [4,5] and human cells (doi:10.1371/journal.pone.0029690; doi:10.1016/j.jgg.2011.08.004 K. Chen et al. (2011 and W.C. Carcamo et al. (2011 ( [6,7]. However, there is little research on the motility of the cytoophidia. Here we selected cytoophidia formed by 6 filament-forming proteins in the budding yeast S. cerevisiae, and performed living-cell imaging of cells expressing the proteins fused with GFP. The dynamic features of the six types of cytoophidia were analyzed. In the data, both raw movies and analysed results of the dynamics of cytoophidia are presented. Keywords: Saccharomyces cerevisiae, CTP synthase, Cytoophidium, Metabolism, Filamentation

Switching the mode of sucrose utilization by Saccharomyces cerevisiae

OpenAIRE

Badotti, Fernanda; Dário, Marcelo G; Alves, Sergio L; Cordioli, Maria Luiza A; Miletti, Luiz C; de Araujo, Pedro S; Stambuk, Boris U

2008-01-01

Abstract Background Overflow metabolism is an undesirable characteristic of aerobic cultures of Saccharomyces cerevisiae during biomass-directed processes. It results from elevated sugar consumption rates that cause a high substrate conversion to ethanol and other bi-products, severely affecting cell physiology, bioprocess performance, and biomass yields. Fed-batch culture, where sucro...

Modifications of Saccharomyces pastorianus cell wall polysaccharides with brewing process.

Science.gov (United States)

Bastos, Rita; Coelho, Elisabete; Coimbra, Manuel A

2015-06-25

The cell wall polysaccharides of brewers spent yeast Saccharomyces pastorianus (BSY) and the inoculum yeast (IY) were studied in order to understand the changes induced by the brewing process. The hot water and alkali extractions performed solubilized mainly mannoproteins, more branched for BSY than those of IY. Also, (31)P solid state NMR showed that the BSY mannoproteins were 3 times more phosphorylated. By electron microscopy it was observed that the final residues of alkali sequential extraction until 4M KOH preserved the yeast three-dimensional structure. The final residues, composed mainly by glucans (92%), showed that the BSY, when compared with IY, contained higher amount of (1→4)-linked Glc (43% for BSY and 16% for IY) and lower (1→3)-linked Glc (17% for BSY and 42% for IY). The enzymatic treatment of final residue showed that both BSY and IY had (α1→4)-linked Glc and (β1→4)-linked Glc, in a 2:1 ratio, showing that S. pastorianus increases their cellulose-like linkages with the brewing process. Copyright © 2015 Elsevier Ltd. All rights reserved.

Use of non-saccharomyces Torulaspora delbrueckii yeast strains in winemaking and brewing

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Tataridis Panagiotis

2013-01-01

Full Text Available Selected Saccharomyces yeast strains have been used for more than 150 years in brewing and for several decades in winemaking. They are necessary in brewing because of the boiling of the wort, which results in the death of all yeast cells, with the exception of some Belgian style beers (ex. Lambic, where the wort is left to be colonized by indigenous yeast and bacteria from the environment and ferment naturally. In winemaking their use is also pertinent because they provide regular and timely fermentations, inhibit the growth of indigenous spoilage microorganisms and contribute to the desired sensory characters. Even though the use of selected Saccharomyces strains provides better quality assurance in winemaking in comparison to the unknown microbial consortia in the must, it has been debated for a long time now whether the use of selected industrial Saccharomyces strains results in wines with less sensory complexity and “terroir” character. In previous decades, non-Saccharomyces yeasts were mainly considered as spoilage/problematic yeast, since they exhibited low fermentation ability and other negative traits. In the last decades experiments have shown that there are some non-Saccharomyces strains (Candida, Pichia, Kluyveromyces, Torulaspora, etc which, even though they are not able to complete the fermentation they can still be used in sequential inoculation-fermentation with Saccharomyces to increase sensory complexity of the wines. Through fermentation in a laboratory scale, we have observed that the overall effects of selected Torulaspora delbrueckii yeast strains, is highly positive, leading to products with pronounced sensory complexity and floral/fruity aroma in winemaking and brewing.

A simple microfluidic platform to study age-dependent protein abundance and localization changes in Saccharomyces cerevisiae

NARCIS (Netherlands)

Cabrera, Margarita; Novarina, Daniele; Rempel, Irina L; Veenhoff, Liesbeth M; Chang, Michael

2017-01-01

The budding yeast Saccharomyces cerevisiae divides asymmetrically, with a smaller daughter cell emerging from its larger mother cell. While the daughter lineage is immortal, mother cells age with each cell division and have a finite lifespan. The replicative ageing of the yeast mother cell has been

Measuring strand discontinuity-directed mismatch repair in yeast Saccharomyces cerevisiae by cell-free nuclear extracts.

Science.gov (United States)

Yuan, Fenghua; Lai, Fangfang; Gu, Liya; Zhou, Wen; El Hokayem, Jimmy; Zhang, Yanbin

2009-05-01

Mismatch repair corrects biosynthetic errors generated during DNA replication, whose deficiency causes a mutator phenotype and directly underlies hereditary non-polyposis colorectal cancer and sporadic cancers. Because of remarkably high conservation of the mismatch repair machinery between the budding yeast (Saccharomyces cerevisiae) and humans, the study of mismatch repair in yeast has provided tremendous insights into the mechanisms of this repair pathway in humans. In addition, yeast cells possess an unbeatable advantage over human cells in terms of the easy genetic manipulation, the availability of whole genome deletion strains, and the relatively low cost for setting up the system. Although many components of eukaryotic mismatch repair have been identified, it remains unclear if additional factors, such as DNA helicase(s) and redundant nuclease(s) besides EXO1, participate in eukaryotic mismatch repair. To facilitate the discovery of novel mismatch repair factors, we developed a straightforward in vitro cell-free repair system. Here, we describe the practical protocols for preparation of yeast cell-free nuclear extracts and DNA mismatch substrates, and the in vitro mismatch repair assay. The validity of the cell-free system was confirmed by the mismatch repair deficient yeast strain (Deltamsh2) and the complementation assay with purified yeast MSH2-MSH6.

Effect of nagilactone E on cell morphology and glucan biosynthesis in budding yeast Saccharomyces cerevisiae.

Science.gov (United States)

Hayashi, Kengo; Yamaguchi, Yoshihiro; Ogita, Akira; Tanaka, Toshio; Kubo, Isao; Fujita, Ken-Ichi

2018-05-14

Nagilactones are norditerpene dilactones isolated from the root bark of Podocarpus nagi. Although nagilactone E has been reported to show antifungal activities, its activity is weaker than that of antifungals on the market. Nagilactone E enhances the antifungal activity of phenylpropanoids such as anethole and isosafrole against nonpathogenic Saccharomyces cerevisiae and pathogenic Candida albicans. However, the detailed mechanisms underlying the antifungal activity of nagilactone E itself have not yet been elucidated. Therefore, we investigated the antifungal mechanisms of nagilactone E using S. cerevisiae. Although nagilactone E induced lethality in vegetatively growing cells, it did not affect cell viability in non-growing cells. Nagilactone E-induced morphological changes in the cells, such as inhomogeneous thickness of the glucan layer and leakage of cytoplasm. Furthermore, a dose-dependent decrease in the amount of newly synthesized (1, 3)-β-glucan was detected in the membrane fractions of the yeast incubated with nagilactone E. These results suggest that nagilactone E exhibits an antifungal activity against S. cerevisiae by depending on cell wall fragility via the inhibition of (1, 3)-β-glucan biosynthesis. Additionally, we confirmed nagilactone E-induced morphological changes of a human pathogenic fungus Aspergillus fumigatus. Therefore, nagilactone E is a potential antifungal drug candidate with fewer adverse effects. Copyright © 2018 Elsevier B.V. All rights reserved.

Advances in metabolic engineering of yeast Saccharomyces cerevisiae for production of chemicals

DEFF Research Database (Denmark)

Borodina, Irina; Nielsen, Jens

2014-01-01

Yeast Saccharomyces cerevisiae is an important industrial host for production of enzymes, pharmaceutical and nutraceutical ingredients and recently also commodity chemicals and biofuels. Here, we review the advances in modeling and synthetic biology tools and how these tools can speed up the deve......Yeast Saccharomyces cerevisiae is an important industrial host for production of enzymes, pharmaceutical and nutraceutical ingredients and recently also commodity chemicals and biofuels. Here, we review the advances in modeling and synthetic biology tools and how these tools can speed up...... the development of yeast cell factories. We also present an overview of metabolic engineering strategies for developing yeast strains for production of polymer monomers: lactic, succinic, and cis,cis-muconic acids. S. cerevisiae has already firmly established itself as a cell factory in industrial biotechnology...

Outward electron transfer by Saccharomyces cerevisiae monitored with a bi-cathodic microbial fuel cell-type activity sensor.

Science.gov (United States)

Ducommun, Raphaël; Favre, Marie-France; Carrard, Delphine; Fischer, Fabian

2010-03-01

A Janus head-like bi-cathodic microbial fuel cell was constructed to monitor the electron transfer from Saccharomyces cerevisiae to a woven carbon anode. The experiments were conducted during an ethanol cultivation of 170 g/l glucose in the presence and absence of yeast-peptone medium. First, using a basic fuel-cell type activity sensor, it was shown that yeast-peptone medium contains electroactive compounds. For this purpose, 1% solutions of soy peptone and yeast extract were subjected to oxidative conditions, using a microbial fuel cell set-up corresponding to a typical galvanic cell, consisting of culture medium in the anodic half-cell and 0.5 M K(3)Fe(CN)(6) in the cathodic half-cell. Second, using a bi-cathodic microbial fuel cell, it was shown that electrons were transferred from yeast cells to the carbon anode. The participation of electroactive compounds in the electron transport was separated as background current. This result was verified by applying medium-free conditions, where only glucose was fed, confirming that electrons are transferred from yeast cells to the woven carbon anode. Knowledge about the electron transfer through the cell membrane is of importance in amperometric online monitoring of yeast fermentations and for electricity production with microbial fuel cells. Copyright (c) 2009 John Wiley & Sons, Ltd.

Factors influencing autolysis of Saccharomyces cerevisiae cells induced by pulsed electric fields.

Science.gov (United States)

Martínez, Juan M; Delso, Carlota; Aguilar, Diederich; Cebrián, Guillermo; Álvarez, Ignacio; Raso, Javier

2018-08-01

The influence of temperature (7-43 °C), pH (3.5-7.0) and ethanol concentration (6-25%) on PEFinduced autolysis and the release of mannose from Saccharomyces cerevisiae was investigated. Changes in the release of intracellular compounds absorbing at 260 nm and 280 nm depended on storage conditions and differed among untreated and PEF-treated cells. For untreated cells, the increase of the Abs 260 and Abs 280 values during 3 weeks of storage was very low when incubated in media of different pH, different ethanol concentrations, or at 7° and 25 °C. Conversely, Abs 260 and Abs 280 values progressively increased for PEF-treated cells stored under the same conditions. Although the PEF treatment intensity was the same in all cases, the amount of intracellular material released depended on incubation conditions. Except for cells stored at 43 °C, for which the concentration of mannose in the media after 21 days was around 90 mg L -1 , the amount of mannose released from untreated cells after 21 days of storage was lower than 60 mg L -1 under all other conditions assayed. After the same incubation time, the amount of mannose released from PEF treated cells ranged from 80 mg L -1 , when they were stored in media with 25% ethanol, to 190 mg L -1 when they were stored at 43 °C. Interaction among assayed factors affecting mannose release was investigated in a medium containing 10% ethanol (v/v) and pH 3.5 for 21 days. Although the interaction of both factors delayed mannose release, the medium containing PEF-treated yeasts had approximately twice the amount of mannoproteins as those containing untreated yeasts. Copyright © 2017 Elsevier Ltd. All rights reserved.

Impact of oxygenation on the performance of three non-Saccharomyces yeasts in co-fermentation with Saccharomyces cerevisiae.

Science.gov (United States)

Shekhawat, Kirti; Bauer, Florian F; Setati, Mathabatha E

2017-03-01

The sequential or co-inoculation of grape must with non-Saccharomyces yeast species and Saccharomyces cerevisiae wine yeast strains has recently become a common practice in winemaking. The procedure intends to enhance unique aroma and flavor profiles of wine. The extent of the impact of non-Saccharomyces strains depends on their ability to produce biomass and to remain metabolically active for a sufficiently long period. However, mixed-culture wine fermentations tend to become rapidly dominated by S. cerevisiae, reducing or eliminating the non-Saccharomyces yeast contribution. For an efficient application of these yeasts, it is therefore essential to understand the environmental factors that modulate the population dynamics of such ecosystems. Several environmental parameters have been shown to influence population dynamics, but their specific effect remains largely uncharacterized. In this study, the population dynamics in co-fermentations of S. cerevisiae and three non-Saccharomyces yeast species: Torulaspora delbrueckii, Lachancea thermotolerans, and Metschnikowia pulcherrima, was investigated as a function of oxygen availability. In all cases, oxygen availability strongly influenced population dynamics, but clear species-dependent differences were observed. Our data show that L. thermotolerans required the least oxygen, followed by T. delbrueckii and M. pulcherrima. Distinct species-specific chemical volatile profiles correlated in all cases with increased persistence of non-Saccharomyces yeasts, in particular increases in some higher alcohols and medium chain fatty acids. The results highlight the role of oxygen in regulating the succession of yeasts during wine fermentations and suggests that more stringent aeration strategies would be necessary to support the persistence of non-Saccharomyces yeasts in real must fermentations.

Gut-targeted immunonutrition boosting natural killer cell activity using Saccharomyces boulardii lysates in immuno-compromised healthy elderly subjects.

Science.gov (United States)

Naito, Yasuhiro; Marotta, Francesco; Kantah, Makoto K; Zerbinati, Nicola; Kushugulova, Almagul; Zhumadilov, Zhaxybay; Illuzzi, Nicola; Sapienza, Chiara; Takadanohara, Hiroshi; Kobayashi, Riyichi; Catanzaro, Roberto

2014-04-01

The aim of this study was to assess the immunomodulatory effect of KC-1317 (a symbiotic mixture containing Saccharomyces boulardii lysate in a cranberry, colostrum-derived lactoferrin, fragaria, and lactose mixture) supplementation in immune-compromised but otherwise healthy elderly subjects. A liquid formulation of KC-1317 was administered in a randomized controlled trial (RCT) fashion to healthy volunteers (65-79 years) previously selected for low natural killer (NK) cell activity, and this parameter was checked at the completion of the study. A significant improvement in NK cell activity of KC-1317 consumers was observed as compared to placebo at the end of 2 months. Although preliminary, these beneficial immune-modulatory effects of KC-1317 in aged individuals might indicate its employment within a wider age-management strategy.

Evaluation of different co-inoculation time of non-Saccharomyces/Saccharomyces yeasts in order to obtain reduced ethanol wines

Directory of Open Access Journals (Sweden)

Mestre María Victoria

2016-01-01

Full Text Available Decreasing ethanol content in wines has become one of the main objectives of winemakers in different areas of the world. The use of selected wine yeasts can be considered one of the most effective and simple tools. The aim of this study was to evaluate the effect of co-inoculation times of selected non-Saccharomyces/Saccharomyces yeasts on the reduction of ethanol levels in wines. Hanseniaspora uvarum BHu9, Starmerella bacillaris BSb55 and Candida membranaefasciens BCm71 were co-inoculate with Saccharomyces cerevisiae under fermentative conditions. Treatments assayed were: pure fermentations of S. cerevisiae BSc203 and non-Saccharomyces yeasts BHu9, BSb55 and BCm71; -co-fermentations: A-BHu9/BSc203; B-BSb55/BSc203 and C-BCm71/BSc203. These co-inoculations were carried out under mixed (simultaneous inoculation, and sequential conditions (non-Saccharomyces yeasts inoculated at initial time and S. cerevisiae at 48, 96 and 144 h. Lower fermentative efficiencies were registered when BHu9 and BSb55 remained pure more time. Conversely, the conversion efficiency was reduced in co-inocula of BCm71/BSc203, when both yeasts interact more time. Metabolites produced during all vinification processes were within acceptable concentration ranges according to the current legislations. Conclusion Time interaction during fermentation processes of non-Saccharomyces and Saccharomyces yeasts showed influence on ethanol production, and this effect would be dependent on the co-inoculated species.

High-level ethanol production from starch by a flocculent Saccharomyces cerevisiae strain displaying cell-surface glucoamylase

Energy Technology Data Exchange (ETDEWEB)

Kondo, A.; Shigechi, H.; Abe, M.; Uyama, K. [Dept. of Chemical Science and Engineering, Kobe Univ., Nadaku, Kobe (Japan); Matsumoto, T.; Fukuda, H. [Div. of Molecular Science, Kobe Univ., Nadaku, Kobe (Japan); Takahashi, S.; Ueda, M.; Tanaka, A. [Dept. of Synthetic Chemistry and Biological Chemistry, Kyoto Univ., Sakyoku, Kyoto (Japan); Kishimoto, M. [Dept. of Biotechnology, Osaka Univ., Osaka (Japan)

2002-07-01

A Strain of host yeast YF207, which is a tryptophan auxotroph and shows strong flocculation ability, was obtained from Saccharomyces diastaticus ATCC60712 and S. cerevisiae W303-1B by tetrad analysis. The plasmid pGA11, which is a multicopy plasmid for cell-surface expression of the Rhyzopus oryzae glucoamylase/{alpha}-agglutinin fusion protein, was then introduced into this flocculent yeast strain (YF207/pGA11). Yeast YF207/pGA11 grew rapidly under aerobic condition (dissolved oxygen 2.0 ppm), using soluble starch. The harvested cells were used for batch fermentation of soluble starch to ethanol under anaerobic condition and showed high ethanol production rates (0.71 g h{sup -1} I{sup -1}) without a time lag, because glucoamylase was immobilized on the yeast cell surface. During repeated utilization of cells for fermentation, YF207/pGA11 maintained high ethanol production rates over 300 h. Moreover, in fed-batch fermentation with YF207/pGA11 for approximately 120 h, the ethanol concentration reached up to 50 g I{sup -1}. In conclusion, flocculent yeast cells displaying cell-surface glucoamylase are considered to be very effective for the direct fermentation of soluble starch to ethanol. (orig.)

Levels of acid-soluble polyphosphate in growing cultures of Saccharomyces cerevisiae.

OpenAIRE

Solimene, R; Guerrini, A M; Donini, P

1980-01-01

Short-chain acid-soluble polyphosphates were extracted from growing cultures of Saccharomyces cerevisiae, and the changes in the levels of these compounds were determined. The production of acid-soluble polyphosphates correlated with the mitochondrial activities since it occurred in two bursts in respiration-competent yeast cells and in only one burst in respiration-deficient yeast cells. The possible role of these compounds is discussed.

Saccharomyces eubayanus and Saccharomyces arboricola reside in North Island native New Zealand forests.

Science.gov (United States)

Gayevskiy, Velimir; Goddard, Matthew R

2016-04-01

Saccharomyces is one of the best-studied microbial genera, but our understanding of the global distributions and evolutionary histories of its members is relatively poor. Recent studies have altered our view of Saccharomyces' origin, but a lack of sampling from the vast majority of the world precludes a holistic perspective. We evaluate alternate Gondwanan and Far East Asian hypotheses concerning the origin of these yeasts. Being part of Gondwana, and only colonized by humans in the last ∼1000 years, New Zealand represents a unique environment for testing these ideas. Genotyping and ribosomal sequencing of samples from North Island native forest parks identified a widespread population of Saccharomyces. Whole genome sequencing identified the presence of S. arboricola and S. eubayanus in New Zealand, which is the first report of S. arboricola outside Far East Asia, and also expands S. eubayanus' known distribution to include the Oceanic region. Phylogenomic approaches place the S. arboricola population as significantly diverged from the only other sequenced Chinese isolate but indicate that S. eubayanus might be a recent migrant from South America. These data tend to support the Far East Asian origin of the Saccharomyces, but the history of this group is still far from clear. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

Raspberry wine fermentation with suspended and immobilized yeast cells of two strains of Saccharomyces cerevisiae.

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Djordjević, Radovan; Gibson, Brian; Sandell, Mari; de Billerbeck, Gustavo M; Bugarski, Branko; Leskošek-Čukalović, Ida; Vunduk, Jovana; Nikićević, Ninoslav; Nedović, Viktor

2015-01-01

The objectives of this study were to assess the differences in fermentative behaviour of two different strains of Saccharomyces cerevisiae (EC1118 and RC212) and to determine the differences in composition and sensory properties of raspberry wines fermented with immobilized and suspended yeast cells of both strains at 15 °C. Analyses of aroma compounds, glycerol, acetic acid and ethanol, as well as the kinetics of fermentation and a sensory evaluation of the wines, were performed. All fermentations with immobilized yeast cells had a shorter lag phase and faster utilization of sugars and ethanol production than those fermented with suspended cells. Slower fermentation kinetics were observed in all the samples that were fermented with strain RC212 (suspended and immobilized) than in samples fermented with strain EC1118. Significantly higher amounts of acetic acid were detected in all samples fermented with strain RC212 than in those fermented with strain EC1118 (0.282 and 0.602 g/l, respectively). Slightly higher amounts of glycerol were observed in samples fermented with strain EC1118 than in those fermented with strain RC212. Copyright © 2014 John Wiley & Sons, Ltd.

Impact of photocatalysis on fungal cells: depiction of cellular and molecular effects on Saccharomyces cerevisiae.

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Thabet, Sana; Simonet, France; Lemaire, Marc; Guillard, Chantal; Cotton, Pascale

2014-12-01

We have investigated the antimicrobial effects of photocatalysis on the yeast model Saccharomyces cerevisiae. To accurately study the antimicrobial mechanisms of the photocatalytic process, we focused our investigations on two questions: the entry of the nanoparticles in treated cells and the fate of the intracellular environment. Transmission electronic microscopy did not reveal any entry of nanoparticles within the cells, even for long exposure times, despite degradation of the cell wall space and deconstruction of cellular compartments. In contrast to proteins located at the periphery of the cells, intracellular proteins did not disappear uniformly. Disappearance or persistence of proteins from the pool of oxidized intracellular isoforms was not correlated to their functions. Altogether, our data suggested that photocatalysis induces the establishment of an intracellular oxidative environment. This hypothesis was sustained by the detection of an increased level of superoxide ions (O2°(-)) in treated cells and by greater cell cultivability for cells expressing oxidant stress response genes during photocatalytic exposure. The increase in intracellular ROS, which was not connected to the entry of nanoparticles within the cells or to a direct contact with the plasma membrane, could be the result of an imbalance in redox status amplified by chain reactions. Moreover, we expanded our study to other yeast and filamentous fungi and pointed out that, in contrast to the laboratory model S. cerevisiae, some environmental strains are very resistant to photocatalysis. This could be related to the cell wall composition and structure. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Apoptosis - Triggering Effects: UVB-irradiation and Saccharomyces cerevisiae.

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Behzadi, Payam; Behzadi, Elham

2012-12-01

The pathogenic disturbance of Saccharomyces cerevisiae is known as a rare but invasive nosocomial fungal infection. This survey is focused on the evaluation of apoptosis-triggering effects of UVB-irradiation in Saccharomyces cerevisiae. The well-growth colonies of Saccharomyces cerevisiae on Sabouraud Dextrose Agar (SDA) were irradiated within an interval of 10 minutes by UVB-light (302 nm). Subsequently, the harvested DNA molecules of control and UV-exposed yeast colonies were run through the 1% agarose gel electrophoresis comprising the luminescent dye of ethidium bromide. No unusual patterns including DNA laddering bands or smears were detected. The applied procedure for UV exposure was not effective for inducing apoptosis in Saccharomyces cerevisiae. So, it needs another UV-radiation protocol for inducing apoptosis phenomenon in Saccharomyces cerevisiae.

Saccharomyces species in the Production of Beer

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Graham G. Stewart

2016-12-01

Full Text Available The characteristic flavour and aroma of any beer is, in large part, determined by the yeast strain employed and the wort composition. In addition, properties such as flocculation, wort fermentation ability (including the uptake of wort sugars, amino acids, and peptides, ethanol and osmotic pressure tolerance together with oxygen requirements have a critical impact on fermentation performance. Yeast management between fermentations is also a critical brewing parameter. Brewer’s yeasts are mostly part of the genus Saccharomyces. Ale yeasts belong to the species Saccharomyces cerevisiae and lager yeasts to the species Saccharomyces pastorianus. The latter is an interspecies hybrid between S. cerevisiae and Saccharomyces eubayanus. Brewer’s yeast strains are facultative anaerobes—they are able to grow in the presence or absence of oxygen and this ability supports their property as an important industrial microorganism. This article covers important aspects of Saccharomyces molecular biology, physiology, and metabolism that is involved in wort fermentation and beer production.

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

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Deutch, Charles E.; Marshall, Pamela A.

2008-01-01

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

The ecology and evolution of non-domesticated Saccharomyces species.

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Boynton, Primrose J; Greig, Duncan

2014-12-01

Yeast researchers need model systems for ecology and evolution, but the model yeast Saccharomyces cerevisiae is not ideal because its evolution has been affected by domestication. Instead, ecologists and evolutionary biologists are focusing on close relatives of S. cerevisiae, the seven species in the genus Saccharomyces. The best-studied Saccharomyces yeast, after S. cerevisiae, is S. paradoxus, an oak tree resident throughout the northern hemisphere. In addition, several more members of the genus Saccharomyces have recently been discovered. Some Saccharomyces species are only found in nature, while others include both wild and domesticated strains. Comparisons between domesticated and wild yeasts have pinpointed hybridization, introgression and high phenotypic diversity as signatures of domestication. But studies of wild Saccharomyces natural history, biogeography and ecology are only beginning. Much remains to be understood about wild yeasts' ecological interactions and life cycles in nature. We encourage researchers to continue to investigate Saccharomyces yeasts in nature, both to place S. cerevisiae biology into its ecological context and to develop the genus Saccharomyces as a model clade for ecology and evolution. © 2014 The Authors. Yeast published by John Wiley & Sons, Ltd.

Chronic action of gamma-radiation on growing cell population of the yeast Saccharomyces cerevisiae at various dose rates

International Nuclear Information System (INIS)

Zyuzikov, N.A.; Petin, V.G.

1996-01-01

Experimental data on the processes of division and death of haploid and diploid yeast Saccharomyces cerevisiae of wild type and of their radiosensitive mutants exposed under optimal for reproduction conditions to chronic gamma-radiation at various dose rates are presented. It is shown that the dependence of the integral division/death process in time was exponential for all the studied strains. With dose rate increasing, the duration of the lag period and the probability of cell inactivation increased, while the multiplication rate decreased. These processes, for equal dose rates, were more expressed for the radiosensitive mutants

Microbially induced separation of quartz from calcite using Saccharomyces cerevisiae.

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Padukone, S Usha; Natarajan, K A

2011-11-01

Cells of Saccharomyces cerevisiae and their metabolites were successfully utilized to achieve selective separation of quartz and calcite through microbially induced flotation and flocculation. S. cerevisiae was adapted to calcite and quartz minerals. Adsorption studies and electrokinetic investigations were carried out to understand the changes in the surface chemistry of yeast cells and the minerals after mutual interaction. Possible mechanisms in microbially induced flotation and flocculation are outlined. Copyright © 2011 Elsevier B.V. All rights reserved.

Expression of TPS1 gene from Saccharomycopsis fibuligera A11 in Saccharomyces sp. W0 enhances trehalose accumulation, ethanol tolerance, and ethanol production.

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Cao, Tian-Shu; Chi, Zhe; Liu, Guang-Lei; Chi, Zhen-Ming

2014-01-01

It has been reported that trehalose plays an important role in stress tolerance in yeasts. Therefore, in order to construct a stably recombinant Saccharomyces sp. W0 with higher ethanol tolerance, the TPS1 gene encoding 6-phosphate-trehalose synthase cloned from Saccharomycopsis fibuligera A11 was ligated into the 18S rDNA integration vector pMIRSC11 and integrated into chromosomal DNA of Saccharomyces sp. W0. The transformant Z8 obtained had the content of 6.23 g of trehalose/100 g of cell dry weight, while Saccharomyces sp. W0 only contained 4.05 g of trehalose/100 g of cell dry weight. The transformant Z8 also had higher ethanol tolerance (cell survival was 25.1 % at 18 ml of ethanol/100 ml of solution) and trehalose-6-phosphate synthase (Tps1) activity (1.3 U/mg) and produced more ethanol (16.4 ml of ethanol/100 ml of medium) than Saccharomyces sp. W0 (cell survival was 12.1 % at 18 ml of ethanol/100 ml of solution, Tps1 activity was 0.8 U/mg and the produced ethanol concentration was 14.2 ml of ethanol/100 ml of medium) under the same conditions. The results show that trehalose indeed can play an important role in ethanol tolerance and ethanol production by Saccharomyces sp. W0.

Combining magnetic sorting of mother cells and fluctuation tests to analyze genome instability during mitotic cell aging in Saccharomyces cerevisiae.

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Patterson, Melissa N; Maxwell, Patrick H

2014-10-16

Saccharomyces cerevisiae has been an excellent model system for examining mechanisms and consequences of genome instability. Information gained from this yeast model is relevant to many organisms, including humans, since DNA repair and DNA damage response factors are well conserved across diverse species. However, S. cerevisiae has not yet been used to fully address whether the rate of accumulating mutations changes with increasing replicative (mitotic) age due to technical constraints. For instance, measurements of yeast replicative lifespan through micromanipulation involve very small populations of cells, which prohibit detection of rare mutations. Genetic methods to enrich for mother cells in populations by inducing death of daughter cells have been developed, but population sizes are still limited by the frequency with which random mutations that compromise the selection systems occur. The current protocol takes advantage of magnetic sorting of surface-labeled yeast mother cells to obtain large enough populations of aging mother cells to quantify rare mutations through phenotypic selections. Mutation rates, measured through fluctuation tests, and mutation frequencies are first established for young cells and used to predict the frequency of mutations in mother cells of various replicative ages. Mutation frequencies are then determined for sorted mother cells, and the age of the mother cells is determined using flow cytometry by staining with a fluorescent reagent that detects bud scars formed on their cell surfaces during cell division. Comparison of predicted mutation frequencies based on the number of cell divisions to the frequencies experimentally observed for mother cells of a given replicative age can then identify whether there are age-related changes in the rate of accumulating mutations. Variations of this basic protocol provide the means to investigate the influence of alterations in specific gene functions or specific environmental conditions on

Cane molasses fermentation for continuous ethanol production in an immobilized cells reactor by Saccharomyces cerevisiae

Energy Technology Data Exchange (ETDEWEB)

Ghorbani, Farshid; Younesi, Habibollah; Esmaeili Sari, Abbas [Department of Environmental Science, Faculty of Natural Resources and Marine Sciences, Tarbiat Modares University, Noor, P.O. Box: 64414-356 (Iran); Najafpour, Ghasem [Department of Chemical Engineering, Faculty of Engineering, Noshirvani University of Technology, Babol (Iran)

2011-02-15

Sodium-alginate immobilized yeast was employed to produce ethanol continuously using cane molasses as a carbon source in an immobilized cell reactor (ICR). The immobilization of Saccharomyces cerevisiae was performed by entrapment of the cell cultured media harvested at exponential growth phase (16 h) with 3% sodium alginate. During the initial stage of operation, the ICR was loaded with fresh beads of mean diameter of 5.01 mm. The ethanol production was affected by the concentration of the cane molasses (50, 100 and 150 g/l), dilution rates (0.064, 0.096, 0.144 and 0.192 h{sup -1}) and hydraulic retention time (5.21, 6.94, 10.42 and 15.63 h) of the media. The pH of the feed medium was set at 4.5 and the fermentation was carried out at an ambient temperature. The maximum ethanol production, theoretical yield (Y{sub E/S}), volumetric ethanol productivity (Q{sub P}) and total sugar consumption was 19.15 g/l, 46.23%, 2.39 g l{sup -1} h{sup -1} and 96%, respectively. (author)

Protein expression of saccharomyces cerevisiae in response to uranium exposure

International Nuclear Information System (INIS)

Sakamoto, Fuminori; Nankawa, Takuya; Kozai, Naofumi; Ohnuki, Toshihiko; Fujii, Tsutomu; Iefuji, Haruyuki; Francis, A.J.

2007-01-01

Protein expression of Saccharomyces cerevisiae grown in the medium containing 238 U (VI) and 233 U (VI) was examined by two-dimensional gel electrophoresis. Saccharomyces cerevisiae of BY4743 was grown in yeast nitrogen base medium containing glucose and glycerol 2-phosphate and 238 U of 0, 2.0, and 5.0 x 10 -4 M or 233 U of 2.5 x 10 -6 M (radioactivity was higher by 350 times than 2.0 x 10 -4 M 238 U) and 5.0 x 10 -6 M for 112 h at 30 degC. The growth of Saccharomyces cerevisiae was monitored by measuring OD 600 at 112 h after the inoculation. Uranium concentrations in the media also were measured by radiometry using a liquid scintillation counter. The growths of the yeast grown in the above media were in the following order: control>2.5 x 10 -6 M 233 U>2.0 x 10 -4 M 238 U>5.0 x 10 -6 M 233 U>5.0 x 10 -4 M 238 U. This result indicated that not only radiological but also chemical effect of U reduced the growth of the yeast. The concentrations of U in the medium containing 238 U or 233 U decreased, suggesting U accumulation by the yeast cells. The 2-D gel electrophoresis analysis showed the appearance of several spots after exposure to 238 U or to 233 U but not in the control containing no uranium. These results show that the yeast cells exposed to U express several specific proteins. (author)

Comparisons of radiosensitivity and damage repair potential between mutants from the Saccharomyces cerevisiae strain of yeast and laboratory-bred wild yeasts with particular attention being given to giant cell formation after X-radiation

International Nuclear Information System (INIS)

Heinen, A.

1988-01-01

Yeast cells were exposed to X-rays at dose levels up to 10 kGy to induce damage to the DNA and investigate its effects on cellular growth patterns. For this purpose, comparisons were carried out between one diploid strain and six haploid strains of the Saccharomyces uvarum and Saccharomyces cerevisiae species, which permitted the individual recovery and damage repair pathways to be described in more detail. The laboratory-bred wild strains ATCC 9080, 211 and 706 were judged to have unimpaired repair mechanisms as compared to the auxotrophs, which fact was evident from the higher radiosensitivity of the latter. A further parameter in this evaluation of growth behaviours was giant cell formation. The results here provided evidence in confirmation of deviations between wild strains and mutants. Even though the ceiling values for the formation of giant cells were similarly high in all strains, impairments of cell division and initial development were observed for the mutants already at considerably lower dose levels. (orig./MG) [de

Cellular radiation effects and hyperthermia cell cycle kinetics of radiation sensitive mutants of saccharomyces cerevisiae after x-irradiation and hyperthermia

International Nuclear Information System (INIS)

Fingerhut, R.; Kiefer, J.; Otto, F.

1983-01-01

Radiosensitive mutants rad2, rad9, and rad51 of Saccharomyces cerevisiae were X-irradiated with 120 Gy or 60 Gy, heated at 50 0 C for 30 min or treated with a combination of both and incubated in nutrient medium at 30 0 C. Cell number, percentage of budding cells, and cell cycle progression were determined in 45-min intervals. Cell cycle kinetics were investigated by flow cytofluorometry. Hyperthermia leads mainly to a lengthening of G1, whereas X-rays arrest cells of the rad2 and rad9 mutant in G2 and the rad51 - mutant additionaly in a state with DNA contents above G2. Cell division dealy is influenced by oxygen in all strains but to a lesser extent in the rad2 mutant. The effect of the combined treatment appears to be merely additive in the rad2 and rad9 mutant while the rad51 mutant is sensitized to X-irradiation by hyperthermia. No selective action of hyperthermia on hypoxic cells was found. (orig.)

Cellular and genetic effects and recovery of heat-damaged cells of Saccharomyces cerevisiae by low intensity electromagnetic radiation at 915 MHz

International Nuclear Information System (INIS)

Sheikh, I.H.

1984-01-01

Studies were conducted on two genetically well known strains of Saccharomyces cerevisiae (Wild Type) and repair deficient mutant (UVS). Results obtained showed clear genetic difference between normal and mutants based on UV sensitivity, percent survival at elevated temperatures and high intensity electromagnetic radiation. At the cellular level, both strains showed a consistent increase in the recovery rate of heat damaged cells when exposed to low intensity FMR as compared to sham (non irradiated cells) at 915 MHz. The percent recovery of wild type was higher than mutant. At the molecular level, the uptake of tritiated uridine into thermally damaged cells which were recovered by low level EMR was significantly higher than sham. Total RNA isolated from irradiated cells and sham showed visible differences in the intensity of RNA bands. Gross quantitative analyses suggest more RNA production in radiation recovered cells as compared to sham. Results presented in this dissertation provide conclusive evidence that low level microwave radiation can be used in the recovery of heat damaged cells

Interpreting suffering from illness: The role of culture and repressive suffering construal.

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Yang, Qian; Liu, Shi; Sullivan, Daniel; Pan, Shengdong

2016-07-01

Mental and physical illnesses are among the most prominent forms of suffering. Cultural worldviews provide tools for making sense of and coping with suffering. In this research, we examine how culture influences both experts' and laypeople's interpretation of suffering from illness. We focus on one type of interpretation of suffering- repressive suffering construal-an interpretation that frames suffering both as the result of immorality on the part of the sufferer and as having the function of maintaining social order by curtailing deviance. We sought to test whether this type of suffering interpretation is more common in cultural ecologies (e.g., urban vs. rural; higher vs. lower status) traditionally associated with collectivist values. Study 1 used data from the General Social Survey to examine variation in suffering interpretation in a representative sample of the U.S. Study 2 examined variation in suffering interpretation with a survey completed by a subsample of Chinese health-care professionals. Study 1 found that U.S. citizens living in a rural environment are more likely to interpret illnesses as being the fault of the sufferer. Study 2 found that those from a lower-SES background are more likely to interpret illnesses in a repressive fashion. In these studies, family size mediates the effect of ecological conditions on RSC. Our research highlights how ecological variables associated with collectivism may bias both laypeople and professionals to interpret suffering from illness in a more repressive way. Copyright © 2016 Elsevier Ltd. All rights reserved.

Saccharomyces cerevisiae of palm wine-enhanced ethanol production by using mutagens

International Nuclear Information System (INIS)

Uma, V.; Polasa, H.

1990-01-01

The newly isolated Saccharomyces cerevisiae of palm wine produced enhanced amounts of ethanol when cells were UV-irradiated and treated with N-methyl-N-nitro-N-nitrosoguanidine. A further increase of ethanol was observed in yeast extract, peptone, dextrose medium fortified with yeast extract, skimmed milk and soya flour. (author). 9 refs

The Stationary-Phase Cells of Saccharomyces cerevisiae Display Dynamic Actin Filaments Required for Processes Extending Chronological Life Span.

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Vasicova, Pavla; Lejskova, Renata; Malcova, Ivana; Hasek, Jiri

2015-11-01

Stationary-growth-phase Saccharomyces cerevisiae yeast cultures consist of nondividing cells that undergo chronological aging. For their successful survival, the turnover of proteins and organelles, ensured by autophagy and the activation of mitochondria, is performed. Some of these processes are engaged in by the actin cytoskeleton. In S. cerevisiae stationary-phase cells, F actin has been shown to form static aggregates named actin bodies, subsequently cited to be markers of quiescence. Our in vivo analyses revealed that stationary-phase cultures contain cells with dynamic actin filaments, besides the cells with static actin bodies. The cells with dynamic actin displayed active endocytosis and autophagy and well-developed mitochondrial networks. Even more, stationary-phase cell cultures grown under calorie restriction predominantly contained cells with actin cables, confirming that the presence of actin cables is linked to successful adaptation to stationary phase. Cells with actin bodies were inactive in endocytosis and autophagy and displayed aberrations in mitochondrial networks. Notably, cells of the respiratory activity-deficient cox4Δ strain displayed the same mitochondrial aberrations and actin bodies only. Additionally, our results indicate that mitochondrial dysfunction precedes the formation of actin bodies and the appearance of actin bodies corresponds to decreased cell fitness. We conclude that the F-actin status reflects the extent of damage that arises from exponential growth. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Sporulation in the Budding Yeast Saccharomyces cerevisiae

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Neiman, Aaron M.

2011-01-01

In response to nitrogen starvation in the presence of a poor carbon source, diploid cells of the yeast Saccharomyces cerevisiae undergo meiosis and package the haploid nuclei produced in meiosis into spores. The formation of spores requires an unusual cell division event in which daughter cells are formed within the cytoplasm of the mother cell. This process involves the de novo generation of two different cellular structures: novel membrane compartments within the cell cytoplasm that give rise to the spore plasma membrane and an extensive spore wall that protects the spore from environmental insults. This article summarizes what is known about the molecular mechanisms controlling spore assembly with particular attention to how constitutive cellular functions are modified to create novel behaviors during this developmental process. Key regulatory points on the sporulation pathway are also discussed as well as the possible role of sporulation in the natural ecology of S. cerevisiae. PMID:22084423

Effect of Saccharomyces, Non-Saccharomyces Yeasts and Malolactic Fermentation Strategies on Fermentation Kinetics and Flavor of Shiraz Wines

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Heinrich du Plessis

2017-12-01

Full Text Available The use of non-Saccharomyces yeasts to improve complexity and diversify wine style is increasing; however, the interactions between non-Saccharomyces yeasts and lactic acid bacteria (LAB have not received much attention. This study investigated the interactions of seven non-Saccharomyces yeast strains of the genera Candida, Hanseniaspora, Lachancea, Metschnikowia and Torulaspora in combination with S. cerevisiae and three malolactic fermentation (MLF strategies in a Shiraz winemaking trial. Standard oenological parameters, volatile composition and sensory profiles of wines were investigated. Wines produced with non-Saccharomyces yeasts had lower alcohol and glycerol levels than wines produced with S. cerevisiae only. Malolactic fermentation also completed faster in these wines. Wines produced with non-Saccharomyces yeasts differed chemically and sensorially from wines produced with S. cerevisiae only. The Candida zemplinina and the one L. thermotolerans isolate slightly inhibited LAB growth in wines that underwent simultaneous MLF. Malolactic fermentation strategy had a greater impact on sensory profiles than yeast treatment. Both yeast selection and MLF strategy had a significant effect on berry aroma, but MLF strategy also had a significant effect on acid balance and astringency of wines. Winemakers should apply the optimal yeast combination and MLF strategy to ensure fast completion of MLF and improve wine complexity.

Vaccinium corymbosum L. (blueberry) extracts exhibit protective action against cadmium toxicity in Saccharomyces cerevisiae cells.

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Oprea, Eliza; Ruta, Lavinia L; Nicolau, Ioana; Popa, Claudia V; Neagoe, Aurora D; Farcasanu, Ileana C

2014-01-01

Blueberries (Vaccinium corymbosum L.) are a rich source of antioxidants and their consumption is believed to contribute to food-related protection against oxidative stress. In the present study, the chemoprotective action of blueberry extracts against cadmium toxicity was investigated using a cadmium-hypersensitive strain of Saccharomyces cerevisiae. Four varieties of blueberries were used in the study, and it was found that the extracts with high content of total anthocyanidins exhibited significant protective effect against the toxicity of cadmium and H2O2. Both the blueberry extracts and pure cyanidin exhibited protective effects against cadmium in a dose-dependent manner, but without significantly interfering with the cadmium accumulation by the yeast cells. The results imply that the blueberry extracts might be a potentially valuable food supplement for individuals exposed to high cadmium. Copyright © 2013 Elsevier Ltd. All rights reserved.

Rethinking Suffering: Allowing for Suffering that is Intrinsic at End of Life.

Science.gov (United States)

Rattner, Maxxine; Berzoff, Joan

2016-01-01

The dilemma so central to the work of providers of palliative and end-of-life care is the paradox of their professional and ethical duty to try to relieve suffering and the limitations of so doing. While the capacity to sit with suffering at the end of life is critical to clinical work, the idea that some intrinsic suffering cannot necessarily always be relieved may model for patients and families that suffering can be borne. Clinicians who encounter unrelievable suffering may feel a sense of failure, helplessness, moral distress, and compassion fatigue. While tolerating suffering runs counter to the aims of palliative care, acknowledging it, bearing it, and validating it may actually help patients and families to do the same. "Sitting with suffering" signals a paradigm shift within the discipline of palliative care, as it asks clinicians to rethink their role in being able to relieve some forms of psychosocial suffering intrinsic to dying.

A temperature-sensitive dcw1 mutant of Saccharomyces cerevisiae is cell cycle arrested with small buds which have aberrant cell walls.

Science.gov (United States)

Kitagaki, Hiroshi; Ito, Kiyoshi; Shimoi, Hitoshi

2004-10-01

Dcw1p and Dfg5p in Saccharomyces cerevisiae are homologous proteins that were previously shown to be involved in cell wall biogenesis and to be essential for growth. Dcw1p was found to be a glycosylphosphatidylinositol-anchored membrane protein. To investigate the roles of these proteins in cell wall biogenesis and cell growth, we constructed mutant alleles of DCW1 by random mutagenesis, introduced them into a Deltadcw1 Deltadfg5 background, and isolated a temperature-sensitive mutant, DC61 (dcw1-3 Deltadfg5). When DC61 cells were incubated at 37 degrees C, most cells had small buds, with areas less than 20% of those of the mother cells. This result indicates that DC61 cells arrest growth with small buds at 37 degrees C. At 37 degrees C, fewer DC61 cells had 1N DNA content and most of them still had a single nucleus located apart from the bud neck. In addition, in DC61 cells incubated at 37 degrees C, bipolar spindles were not formed. These results indicate that DC61 cells, when incubated at 37 degrees C, are cell cycle arrested after DNA replication and prior to the separation of spindle pole bodies. The small buds of DC61 accumulated chitin in the bud cortex, and some of them were lysed, which indicates that they had aberrant cell walls. A temperature-sensitive dfg5 mutant, DF66 (Deltadcw1 dfg5-29), showed similar phenotypes. DCW1 and DFG5 mRNA levels peaked in the G1 and S phases, respectively. These results indicate that Dcw1p and Dfg5p are involved in bud formation through their involvement in biogenesis of the bud cell wall.

Kluyveromyces marxianus and Saccharomyces boulardii Induce Distinct Levels of Dendritic Cell Cytokine Secretion and Significantly Different T Cell Responses In Vitro.

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Ida M Smith

Full Text Available Interactions between members of the intestinal microbiota and the mucosal immune system can significantly impact human health, and in this context, fungi and food-related yeasts are known to influence intestinal inflammation through direct interactions with specialized immune cells in vivo. The aim of the present study was to characterize the immune modulating properties of the food-related yeast Kluyveromyces marxianus in terms of adaptive immune responses indicating inflammation versus tolerance and to explore the mechanisms behind the observed responses. Benchmarking against a Saccharomyces boulardii strain with probiotic effects documented in clinical trials, we evaluated the ability of K. marxianus to modulate human dendritic cell (DC function in vitro. Further, we assessed yeast induced DC modulation of naive T cells toward effector responses dominated by secretion of IFNγ and IL-17 versus induction of a Treg response characterized by robust IL-10 secretion. In addition, we blocked relevant DC surface receptors and investigated the stimulating properties of β-glucan containing yeast cell wall extracts. K. marxianus and S. boulardii induced distinct levels of DC cytokine secretion, primarily driven by Dectin-1 recognition of β-glucan components in their cell walls. Upon co-incubation of yeast exposed DCs and naive T cells, S. boulardii induced a potent IFNγ response indicating TH1 mobilization. In contrast, K. marxianus induced a response dominated by Foxp3+ Treg cells, a characteristic that may benefit human health in conditions characterized by excessive inflammation and positions K. marxianus as a strong candidate for further development as a novel yeast probiotic.

Kluyveromyces marxianus and Saccharomyces boulardii Induce Distinct Levels of Dendritic Cell Cytokine Secretion and Significantly Different T Cell Responses In Vitro.

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Smith, Ida M; Baker, Adam; Christensen, Jeffrey E; Boekhout, Teun; Frøkiær, Hanne; Arneborg, Nils; Jespersen, Lene

2016-01-01

Interactions between members of the intestinal microbiota and the mucosal immune system can significantly impact human health, and in this context, fungi and food-related yeasts are known to influence intestinal inflammation through direct interactions with specialized immune cells in vivo. The aim of the present study was to characterize the immune modulating properties of the food-related yeast Kluyveromyces marxianus in terms of adaptive immune responses indicating inflammation versus tolerance and to explore the mechanisms behind the observed responses. Benchmarking against a Saccharomyces boulardii strain with probiotic effects documented in clinical trials, we evaluated the ability of K. marxianus to modulate human dendritic cell (DC) function in vitro. Further, we assessed yeast induced DC modulation of naive T cells toward effector responses dominated by secretion of IFNγ and IL-17 versus induction of a Treg response characterized by robust IL-10 secretion. In addition, we blocked relevant DC surface receptors and investigated the stimulating properties of β-glucan containing yeast cell wall extracts. K. marxianus and S. boulardii induced distinct levels of DC cytokine secretion, primarily driven by Dectin-1 recognition of β-glucan components in their cell walls. Upon co-incubation of yeast exposed DCs and naive T cells, S. boulardii induced a potent IFNγ response indicating TH1 mobilization. In contrast, K. marxianus induced a response dominated by Foxp3+ Treg cells, a characteristic that may benefit human health in conditions characterized by excessive inflammation and positions K. marxianus as a strong candidate for further development as a novel yeast probiotic.

Saccharomyces uvarum is responsible for the traditional fermentation of apple chicha in Patagonia.

Science.gov (United States)

Rodríguez, Maria E; Pérez-Través, Laura; Sangorrín, Marcela P; Barrio, Eladio; Querol, Amparo; Lopes, Christian A

2017-01-01

Apple chicha is a fresh low alcoholic beverage elaborated by aboriginal communities of Andean Patagonia (Argentina and Chile). In the present work, we identified the yeast microbiota associated with this fermentation, and characterized genetically those belonging to the genus Saccharomyces. Both Saccharomyces cerevisiae and S. uvarum were found in the analyzed fermentations. Phylogenetic and population structure analyses based on genes sequence analysis were carried out for both S. cerevisiae and S. uvarum strains obtained in this study and a set of additional strains from diverse origins. The results demonstrate that S. cerevisiae strains from apple chicha belong to the big group of wine/European strains of this species, while S. uvarum strains were included in the Holartic population of this species. Additionally, some S. uvarum strains from chichas evidenced as an admixture of both pure Holartic and pure South American populations. Our results suggest that Holartic strains could have been introduced in South America together with the domestication of apple trees by Mapuche communities. This Holartic population suffered admixis with the naturally present South American population of this species, originating strains bearing genetic features from the two populations, detectable in both chichas and natural habitats. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Aged mother cells of Saccharomyces cerevisiae show markers of oxidative stress and apoptosis

Czech Academy of Sciences Publication Activity Database

Laun, P.; Pichová, Alena; Madeo, F.; Fuchs, J.; Ellinger, A.; Kohlwein, S.; Dawes, I.; Fröhlich, K. U.; Breitenbach, M.

2001-01-01

Roč. 39, č. 5 (2001), s. 1166-1173 ISSN 0950-382X R&D Projects: GA ČR GA204/97/0541 Institutional research plan: CEZ:AV0Z5020903 Keywords : Saccharomyces cerevisiae * genetic changes Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 6.398, year: 2001

Vacuolar H+-ATPase Protects Saccharomyces cerevisiae Cells against Ethanol-Induced Oxidative and Cell Wall Stresses.

Science.gov (United States)

Charoenbhakdi, Sirikarn; Dokpikul, Thanittra; Burphan, Thanawat; Techo, Todsapol; Auesukaree, Choowong

2016-05-15

During fermentation, increased ethanol concentration is a major stress for yeast cells. Vacuolar H(+)-ATPase (V-ATPase), which plays an important role in the maintenance of intracellular pH homeostasis through vacuolar acidification, has been shown to be required for tolerance to straight-chain alcohols, including ethanol. Since ethanol is known to increase membrane permeability to protons, which then promotes intracellular acidification, it is possible that the V-ATPase is required for recovery from alcohol-induced intracellular acidification. In this study, we show that the effects of straight-chain alcohols on membrane permeabilization and acidification of the cytosol and vacuole are strongly dependent on their lipophilicity. These findings suggest that the membrane-permeabilizing effect of straight-chain alcohols induces cytosolic and vacuolar acidification in a lipophilicity-dependent manner. Surprisingly, after ethanol challenge, the cytosolic pH in Δvma2 and Δvma3 mutants lacking V-ATPase activity was similar to that of the wild-type strain. It is therefore unlikely that the ethanol-sensitive phenotype of vma mutants resulted from severe cytosolic acidification. Interestingly, the vma mutants exposed to ethanol exhibited a delay in cell wall remodeling and a significant increase in intracellular reactive oxygen species (ROS). These findings suggest a role for V-ATPase in the regulation of the cell wall stress response and the prevention of endogenous oxidative stress in response to ethanol. The yeast Saccharomyces cerevisiae has been widely used in the alcoholic fermentation industry. Among the environmental stresses that yeast cells encounter during the process of alcoholic fermentation, ethanol is a major stress factor that inhibits yeast growth and viability, eventually leading to fermentation arrest. This study provides evidence for the molecular mechanisms of ethanol tolerance, which is a desirable characteristic for yeast strains used in alcoholic

Saccharomyces cerevisiae GTPase complex: Gtr1p-Gtr2p regulates cell-proliferation through Saccharomyces cerevisiae Ran-binding protein, Yrb2p

International Nuclear Information System (INIS)

Wang Yonggang; Nakashima, Nobutaka; Sekiguchi, Takeshi; Nishimoto, Takeharu

2005-01-01

A Gtr1p GTPase, the GDP mutant of which suppresses both temperature-sensitive mutants of Saccharomyces cerevisiae RanGEF/Prp20p and RanGAP/Rna1p, was presently found to interact with Yrb2p, the S. cerevisiae homologue of mammalian Ran-binding protein 3. Gtr1p bound the Ran-binding domain of Yrb2p. In contrast, Gtr2p, a partner of Gtr1p, did not bind Yrb2p, although it bound Gtr1p. A triple mutant: yrb2Δ gtr1Δ gtr2Δ was lethal, while a double mutant: gtr1Δ gtr2Δ survived well, indicating that Yrb2p protected cells from the killing effect of gtr1Δ gtr2Δ. Recombinant Gtr1p and Gtr2p were purified as a complex from Escherichia coli. The resulting Gtr1p-Gtr2p complex was comprised of an equal amount of Gtr1p and Gtr2p, which inhibited the Rna1p/Yrb2 dependent RanGAP activity. Thus, the Gtr1p-Gtr2p cycle was suggested to regulate the Ran cycle through Yrb2p

Glucose repression in Saccharomyces cerevisiae.

Science.gov (United States)

Kayikci, Ömur; Nielsen, Jens

2015-09-01

Glucose is the primary source of energy for the budding yeast Saccharomyces cerevisiae. Although yeast cells can utilize a wide range of carbon sources, presence of glucose suppresses molecular activities involved in the use of alternate carbon sources as well as it represses respiration and gluconeogenesis. This dominant effect of glucose on yeast carbon metabolism is coordinated by several signaling and metabolic interactions that mainly regulate transcriptional activity but are also effective at post-transcriptional and post-translational levels. This review describes effects of glucose repression on yeast carbon metabolism with a focus on roles of the Snf3/Rgt2 glucose-sensing pathway and Snf1 signal transduction in establishment and relief of glucose repression. © FEMS 2015.

AMIODARONE INDUCES THE SYNTHESIS OF HSPS IN SACCHAROMYCES CEREVISIAE AND ARABIDOPSIS THALIANA CELLS

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Pyatrikas D.V.

2012-08-01

Full Text Available Many biotic and abiotic stresses cause an increase of cytosolic Ca2+ level in cells. Calcium is one of the most important second messengers, regulating many various activities in the cell and was known to affect expression of stress activated genes. Mild heat shock induces the expression of heat shock proteins (Hsps which protect cell from drastic heat shock exposure. There are some literature data permitting to suggest that transient elevation of cytosolic Ca2+ level in plant cells is important for activation of Hsps expression. On the other hand mitochondria are known to regulate the intracellular calcium and reactive oxygen species signaling. It has been shown recently that mild heat shock induces hyperpolarization of inner mitochondrial membrane in plant and yeast cells and this event is critically important for activation of Hsps expression. To reveal the relationship between mitochondrial activity, intracellular calcium homeostasis and Hsps expression an antiarrhythmic drug amiodarone (AMD have been used. AMD is known to cause transient increase of cytosolic Ca2+ level in Saccharomyces cerevisiae. Obtained results have showed that AMD treatment induced the synthesis of Hsp104p in S. cerevisiae cells and Hsp101p in A. thaliana cell culture. Induction of Hsp104p synthesis leads to enhanced yeast capability to survive lethal heat shock exposure. Development of S. cerevisiae thermotolerance depended significantly on the presence of Hsp104p. Elevation of Hsp104p level in the result of AMD treatment was shown to be governed by activity of Msn2p and Msn4p transcription factors. Deletion of the MSN2 and MSN4 genes abrogated the AMD ability to induce Hsp104p synthesis. Mild heat shock and AMD treatment induced the hyperpolarization of the inner mitochondrial membrane in yeast and Arabidopsis cells which accompanied by HSP synthesis and development of thermotolerance. It was suggested that increase of cytosolic Ca2+ level after AMD treatment

Saccharomyces boulardii improves intestinal epithelial cell restitution by inhibiting αvβ5 integrin activation state.

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Alexandra Canonici

Full Text Available Intestinal epithelial cell damage is frequently seen in the mucosal lesions of infectious or inflammatory bowel diseases such as ulcerative colitis or Crohn's disease. Complete remission of these diseases requires both the disappearance of inflammation and the repair of damaged epithelium. Saccharomyces boulardii (Sb, Biocodex is a non-pathogenic yeast widely used as a preventive and therapeutic probiotic for the prevention and treatment of diarrhea and other gastrointestinal disorders. We recently showed that it enhances the repair of intestinal epithelium through activation of α2β1 integrin collagen receptors. In the present study, we demonstrated that α2β1 integrin is not the sole cell-extracellular matrix receptor involved during Sb-mediated intestinal restitution. Indeed, by using cell adhesion assays, we showed that Sb supernatant contains heat sensitive molecule(s, with a molecular weight higher than 9 kDa, which decreased αvβ5 integrin-mediated adhesion to vitronectin by competing with the integrin. Moreover, Sb-mediated changes in cell adhesion to vitronectin resulted in a reduction of the αvβ5signaling pathway. We used a monolayer wounding assay that mimics in vivo cell restitution to demonstrate that down-modulation of the αvβ5 integrin-vitronectin interaction is related to Sb-induced cell migration. We therefore postulated that Sb supernatant contains motogenic factors that enhance cell restitution through multiple pathways, including the dynamic fine regulation of αvβ5 integrin binding activity. This could be of major importance in diseases characterized by severe mucosal injury, such as inflammatory and infectious bowel diseases.

Effects of fermentation by Saccharomyces cerevisiae and ...

African Journals Online (AJOL)

yassine

2013-02-13

Feb 13, 2013 ... Full Length Research Paper. Effect of Saccharomyces cerevisiae fermentation on the ... 2003). Besides, several alcoholic beverages such as wine or liqueurs are obtained from fruit juices fermented by Saccharomyces ..... (2003). Kinetics of pigment release from hairy root cultures of Beta vulgaris under the ...

A vaccine grade of yeast Saccharomyces cerevisiae expressing mammalian myostatin

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Zhang Tingting

2012-12-01

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

Intracellular metabolite profiling of Saccharomyces cerevisiae evolved under furfural

OpenAIRE

Jung, Young Hoon; Kim, Sooah; Yang, Jungwoo; Seo, Jin?Ho; Kim, Kyoung Heon

2016-01-01

Summary Furfural, one of the most common inhibitors in pre?treatment hydrolysates, reduces the cell growth and ethanol production of yeast. Evolutionary engineering has been used as a selection scheme to obtain yeast strains that exhibit furfural tolerance. However, the response of Saccharomyces cerevisiae to furfural at the metabolite level during evolution remains unknown. In this study, evolutionary engineering and metabolomic analyses were applied to determine the effects of furfural on y...

Two NAD-linked redox shuttles maintain the peroxisomal redox balance in Saccharomyces cerevisiae

NARCIS (Netherlands)

Al-Saryi, Nadal A.; Al-Hejjaj, Murtakab Y.; van Roermund, Carlo W. T.; Hulmes, Georgia E.; Ekal, Lakhan; Payton, Chantell; Wanders, Ronald J. A.; Hettema, Ewald H.

2017-01-01

In Saccharomyces cerevisiae, peroxisomes are the sole site of fatty acid beta-oxidation. During this process, NAD(+) is reduced to NADH. When cells are grown on oleate medium, peroxisomal NADH is reoxidised to NAD(+) by malate dehydrogenase (Mdh3p) and reduction equivalents are transferred to the

Saccharomyces eubayanus and Saccharomyces uvarum associated with the fermentation of Araucaria araucana seeds in Patagonia.

Science.gov (United States)

Rodríguez, M Eugenia; Pérez-Través, Laura; Sangorrín, Marcela P; Barrio, Eladio; Lopes, Christian A

2014-09-01

Mudai is a traditional fermented beverage, made from the seeds of the Araucaria araucana tree by Mapuche communities. The main goal of the present study was to identify and characterize the yeast microbiota responsible of Mudai fermentation as well as from A. araucana seeds and bark from different locations in Northern Patagonia. Only Hanseniaspora uvarum and a commercial bakery strain of Saccharomyces cerevisiae were isolated from Mudai and all Saccharomyces isolates recovered from A. araucana seed and bark samples belonged to the cryotolerant species Saccharomyces eubayanus and Saccharomyces uvarum. These two species were already reported in Nothofagus trees from Patagonia; however, this is the first time that they were isolated from A. araucana, which extends their ecological distribution. The presence of these species in A. araucana seeds and bark samples, led us to postulate a potential role for them as the original yeasts responsible for the elaboration of Mudai before the introduction of commercial S. cerevisiae cultures. The molecular and genetic characterization of the S. uvarum and S. eubayanus isolates and their comparison with European S. uvarum strains and S. eubayanus hybrids (S. bayanus and S. pastorianus), allowed their ecology and evolution us to be examined. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Pretreatment with Saccharomyces boulardii does not prevent the experimental mucositis in Swiss mice.

Science.gov (United States)

Maioli, Tatiani Uceli; de Melo Silva, Brenda; Dias, Michelle Nobre; Paiva, Nivea Carolina; Cardoso, Valbert Nascimento; Fernandes, Simone Odilia; Carneiro, Cláudia Martins; Dos Santos Martins, Flaviano; de Vasconcelos Generoso, Simone

2014-04-11

The antimetabolite chemotherapy 5-Fluorouracil is one of the most commonly prescribed drugs in clinical cancer treatment. Although this drug is not specific for cancer cells and also acts on healthy cells, it can cause mucositis, a common collateral effect. Dysbiosis has also been described in 5-fluorouracil-induced mucositis and is likely to contribute to the overall development of mucositis. In light of this theory, the use of probiotics could be a helpful strategy to alleviate mucositis. So the aim of this study was evaluate the impact of the probiotic Saccharomyces boulardii in a model of mucositis. After induced of mucositis, mice from the Mucositis groups showed a decrease in food consumption (p Saccharomyces boulardii did not reverse this effect (p > 0.05). Mucositis induced an increase in intestinal permeability and intestinal inflammation (p  0.05) in mice pretreated with S. boulardii. S. boulardii was not able to prevent the effects of experimental mucositis induced by 5- Fluorouracil.

Production of single cell protein (SCP) from food and agricultural waste by using Saccharomyces cerevisiae.

Science.gov (United States)

Gervasi, Teresa; Pellizzeri, Vito; Calabrese, Giorgio; Di Bella, Giuseppa; Cicero, Nicola; Dugo, Giacomo

2018-03-01

Food waste is the single-largest component of the waste stream, in order to protect and safeguard the public health, useful and innovative recycling methods are investigated. The conversion of food wastes in value-added products is becoming a more economically viable and interesting practice. Food waste, collected in the distribution sector and citrus industries, was characterised for its potential as a raw material to use in fermentation processes. In this study, the production of single-cell protein (SCP) using food waste as a substrate was investigated. The purpose of this study has been to produce SCP from mixtures of food waste using Saccharomyces cerevisiae. The main fermentation test was carried out using a 25 l bioreactor. The utilisation of food waste can allow us to not only to reduce environmental pollution, but also to obtain value-added products such as protein supply for animal feed.

Outlining a future for non-Saccharomyces yeasts: selection of putative spoilage wine strains to be used in association with Saccharomyces cerevisiae for grape juice fermentation.

Science.gov (United States)

Domizio, Paola; Romani, Cristina; Lencioni, Livio; Comitini, Francesca; Gobbi, Mirko; Mannazzu, Ilaria; Ciani, Maurizio

2011-06-30

The use of non-Saccharomyces yeasts that are generally considered as spoilage yeasts, in association with Saccharomyces cerevisiae for grape must fermentation was here evaluated. Analysis of the main oenological characteristics of pure cultures of 55 yeasts belonging to the genera Hanseniaspora, Pichia, Saccharomycodes and Zygosaccharomyces revealed wide biodiversity within each genus. Moreover, many of these non-Saccharomyces strains had interesting oenological properties in terms of fermentation purity, and ethanol and secondary metabolite production. The use of four non-Saccharomyces yeasts (one per genus) in mixed cultures with a commercial S. cerevisiae strain at different S. cerevisiae/non-Saccharomyces inoculum ratios was investigated. This revealed that most of the compounds normally produced at high concentrations by pure cultures of non-Saccharomyces, and which are considered detrimental to wine quality, do not reach threshold taste levels in these mixed fermentations. On the other hand, the analytical profiles of the wines produced by these mixed cultures indicated that depending on the yeast species and the S. cerevisiae/non-Saccharomyces inoculum ratio, these non-Saccharomyces yeasts can be used to increase production of polysaccharides and to modulate the final concentrations of acetic acid and volatile compounds, such as ethyl acetate, phenyl-ethyl acetate, 2-phenyl ethanol, and 2-methyl 1-butanol. Copyright © 2011 Elsevier B.V. All rights reserved.

A population study of killer viruses reveals different evolutionary histories of two closely related Saccharomyces sensu stricto yeasts.

Science.gov (United States)

Chang, Shang-Lin; Leu, Jun-Yi; Chang, Tien-Hsien

2015-08-01

Microbes have evolved ways of interference competition to gain advantage over their ecological competitors. The use of secreted killer toxins by yeast cells through acquiring double-stranded RNA viruses is one such prominent example. Although the killer behaviour has been well studied in laboratory yeast strains, our knowledge regarding how killer viruses are spread and maintained in nature and how yeast cells co-evolve with viruses remains limited. We investigated these issues using a panel of 81 yeast populations belonging to three Saccharomyces sensu stricto species isolated from diverse ecological niches and geographic locations. We found that killer strains are rare among all three species. In contrast, killer toxin resistance is widespread in Saccharomyces paradoxus populations, but not in Saccharomyces cerevisiae or Saccharomyces eubayanus populations. Genetic analyses revealed that toxin resistance in S. paradoxus is often caused by dominant alleles that have independently evolved in different populations. Molecular typing identified one M28 and two types of M1 killer viruses in those killer strains. We further showed that killer viruses of the same type could lead to distinct killer phenotypes under different host backgrounds, suggesting co-evolution between the viruses and hosts in different populations. Taken together, our data suggest that killer viruses vary in their evolutionary histories even within closely related yeast species. © 2015 John Wiley & Sons Ltd.

Role of DNA damage in ultraviolet (313 nm) inactivation of yeasts Saccharomyces cerevisial

International Nuclear Information System (INIS)

Pospelov, M.E.; Ivanova, Eh.V.; Frajkin, G.Ya.

1984-01-01

Relative contribution of photoinhibition of cell respiration and DNA damage to lethal effect, caused by ultraviolet (UV) radiation of 313 m in certain yeast strains Saccharomyces cerevisiae, has been studied. It is shown that cell inactivation is mainly conditioned by DNA photodamage. When studying photoreactivation it has been established, that dimers of pyrimidine bases are the main lethal photoproducts, formed in DNA Under the effect of UV-radiation of 313 nm

Genomic insights into the Saccharomyces sensu stricto complex.

Science.gov (United States)

Borneman, Anthony R; Pretorius, Isak S

2015-02-01

The Saccharomyces sensu stricto group encompasses species ranging from the industrially ubiquitous yeast Saccharomyces cerevisiae to those that are confined to geographically limited environmental niches. The wealth of genomic data that are now available for the Saccharomyces genus is providing unprecedented insights into the genomic processes that can drive speciation and evolution, both in the natural environment and in response to human-driven selective forces during the historical "domestication" of these yeasts for baking, brewing, and winemaking. Copyright © 2015 by the Genetics Society of America.

Saccharomyces cerevisiae var. boulardii fungemia following probiotic treatment

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Marcelo C. Appel-da-Silva

2017-12-01

Full Text Available Probiotics are commonly prescribed as an adjuvant in the treatment of antibiotic-associated diarrhea caused by Clostridium difficile. We report the case of an immunocompromised 73-year-old patient on chemotherapy who developed Saccharomyces cerevisiae var. boulardii fungemia in a central venous catheter during treatment of antibiotic-associated pseudomembranous colitis with the probiotic Saccharomyces cerevisiae var. boulardii. Fungemia was resolved after interruption of probiotic administration without the need to replace the central venous line. Keywords: Saccharomyces, Probiotics, Fungemia, Critical illness, Clostridium difficile

Growth rate-regulated expression of the hexose transporter HXT5 in Saccharomyces cerevisiae

NARCIS (Netherlands)

Verwaal, René

2003-01-01

Glucose, which is the most preferred carbon source for the yeast Saccharomyces cerevisiae, is transported across the plasma membrane into cells by hexose transporter (Hxt) proteins. The Hxt proteins are encoded by a multigene family consisting of 20 members. It was shown previously that HXT1-4 and

Mitochondrial genomic dysfunction causes dephosphorylation of Sch9 in the yeast Saccharomyces cerevisiae.

Science.gov (United States)

Kawai, Shigeyuki; Urban, Jörg; Piccolis, Manuele; Panchaud, Nicolas; De Virgilio, Claudio; Loewith, Robbie

2011-10-01

TORC1-dependent phosphorylation of Saccharomyces cerevisiae Sch9 was dramatically reduced upon exposure to a protonophore or in respiration-incompetent ρ(0) cells but not in respiration-incompetent pet mutants, providing important insight into the molecular mechanisms governing interorganellar signaling in general and retrograde signaling in particular.

Manipulation of malic enzyme in Saccharomyces cerevisiae for increasing NADPH production capacity aerobically in different cellular compartments

DEFF Research Database (Denmark)

Santos, Maria Margarida M. dos; Vijayendran, Raghevendran; Kotter, P.

2004-01-01

The yeast Saccharomyces cerevisiae is an attractive cell factory, but in many cases there are constraints related with balancing the formation and consumption of redox cofactors. In this work, we studied the effect of having an additional source of NADPH in the cell. In order to do this, two...

Role of anti-competitor toxins in the origin and maintenance of diversity in Saccharomyces yeast microbial populations

NARCIS (Netherlands)

Pieczynska, M.D.

2015-01-01

Abstract

Saccharomyces cells occasionally carry cytoplasmic ds-RNA “killer” viruses coding for low-mass proteins, which upon secretion to the environment can kill related cells that do not carry the viral particles. Such killer viruses are not infectious,

Anethole induces apoptotic cell death accompanied by reactive oxygen species production and DNA fragmentation in Aspergillus fumigatus and Saccharomyces cerevisiae.

Science.gov (United States)

Fujita, Ken-Ichi; Tatsumi, Miki; Ogita, Akira; Kubo, Isao; Tanaka, Toshio

2014-02-01

trans-Anethole (anethole), a major component of anise oil, has a broad antimicrobial spectrum, and antimicrobial activity that is weaker than that of other antibiotics on the market. When combined with polygodial, nagilactone E, and n-dodecanol, anethole has been shown to possess significant synergistic antifungal activity against a budding yeast, Saccharomyces cerevisiae, and a human opportunistic pathogenic yeast, Candida albicans. However, the antifungal mechanism of anethole has not been completely determined. We found that anethole stimulated cell death of a human opportunistic pathogenic fungus, Aspergillus fumigatus, in addition to S. cerevisiae. The anethole-induced cell death was accompanied by reactive oxygen species production, metacaspase activation, and DNA fragmentation. Several mutants of S. cerevisiae, in which genes related to the apoptosis-initiating execution signals from mitochondria were deleted, were resistant to anethole. These results suggest that anethole-induced cell death could be explained by oxidative stress-dependent apoptosis via typical mitochondrial death cascades in fungi, including A. fumigatus and S. cerevisiae. © 2014 FEBS.

Mitotic chromosome loss in a radiation-sensitive strain of the yeast Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Mortimer, R.K.; Contopoulou, R.; Schild, D.

1981-01-01

Cells of Saccharomyces cerevisiae with mutations in the RAD52 gene have previously been shown to be defective in meiotic and mitotic recombination, in sporulation, and in repair of radiation-induced damage to DNA. In this study we show that diploid cells homozygous for rad52 lose chromosomes at high frequencies and that these frequencies of loss can be increased dramatically by exposure of these cells to x-rays. Genetic analyses of survivors of x-ray treatment demonstrate that chromosome loss events result in the conversion of diploid cells to cells with near haploid chromosome numbers

The Saccharomyces boulardii CNCM I-745 Strain Shows Protective Effects against the B. anthracis LT Toxin

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Rodolphe Pontier-Bres

2015-10-01

Full Text Available The probiotic yeast Saccharomyces boulardii (S. boulardii has been prescribed for the prophylaxis and treatment of several infectious diarrheal diseases. Gastrointestinal anthrax causes fatal systemic disease. In the present study, we investigated the protective effects conferred by Saccharomyces boulardii CNCM I-745 strain on polarized T84 columnar epithelial cells intoxicated by the lethal toxin (LT of Bacillus anthracis. Exposure of polarized T84 cells to LT affected cell monolayer integrity, modified the morphology of tight junctions and induced the formation of actin stress fibers. Overnight treatment of cells with S. boulardii before incubation with LT maintained the integrity of the monolayers, prevented morphological modification of tight junctions, restricted the effects of LT on actin remodeling and delayed LT-induced MEK-2 cleavage. Mechanistically, we demonstrated that in the presence of S. boulardii, the medium is depleted of both LF and PA sub-units of LT and the appearance of a cleaved form of PA. Our study highlights the potential of the S. boulardii CNCM I-745 strain as a prophylactic agent against the gastrointestinal form of anthrax.

The Saccharomyces boulardii CNCM I-745 strain shows protective effects against the B. anthracis LT toxin.

Science.gov (United States)

Pontier-Bres, Rodolphe; Rampal, Patrick; Peyron, Jean-François; Munro, Patrick; Lemichez, Emmanuel; Czerucka, Dorota

2015-10-30

The probiotic yeast Saccharomyces boulardii (S. boulardii) has been prescribed for the prophylaxis and treatment of several infectious diarrheal diseases. Gastrointestinal anthrax causes fatal systemic disease. In the present study, we investigated the protective effects conferred by Saccharomyces boulardii CNCM I-745 strain on polarized T84 columnar epithelial cells intoxicated by the lethal toxin (LT) of Bacillus anthracis. Exposure of polarized T84 cells to LT affected cell monolayer integrity, modified the morphology of tight junctions and induced the formation of actin stress fibers. Overnight treatment of cells with S. boulardii before incubation with LT maintained the integrity of the monolayers, prevented morphological modification of tight junctions, restricted the effects of LT on actin remodeling and delayed LT-induced MEK-2 cleavage. Mechanistically, we demonstrated that in the presence of S. boulardii, the medium is depleted of both LF and PA sub-units of LT and the appearance of a cleaved form of PA. Our study highlights the potential of the S. boulardii CNCM I-745 strain as a prophylactic agent against the gastrointestinal form of anthrax.

[Christian dimension of suffering].

Science.gov (United States)

Kubik, K

1999-01-01

Human existence is marked by imperfection, whose expression--among other things--is suffering. The problem of answering the question about the meaning of suffering for human life in its entirety is of great significance in philosophy and theology. In the Old Testament it meant God's punishment for the evil done by man. In Christianity this bleak notion of suffering has found a new dimension--suffering is creative, redemptive in character; it enables a man to surpass his limits. The understanding of suffering and its sense has a profound meaning in building a suitable attitude of a sick person towards his own weakness.

Saccharomyces genome database informs human biology

OpenAIRE

Skrzypek, Marek S; Nash, Robert S; Wong, Edith D; MacPherson, Kevin A; Hellerstedt, Sage T; Engel, Stacia R; Karra, Kalpana; Weng, Shuai; Sheppard, Travis K; Binkley, Gail; Simison, Matt; Miyasato, Stuart R; Cherry, J Michael

2017-01-01

Abstract The Saccharomyces Genome Database (SGD; http://www.yeastgenome.org) is an expertly curated database of literature-derived functional information for the model organism budding yeast, Saccharomyces cerevisiae. SGD constantly strives to synergize new types of experimental data and bioinformatics predictions with existing data, and to organize them into a comprehensive and up-to-date information resource. The primary mission of SGD is to facilitate research into the biology of yeast and...

Characterization of an MMS sensitive mutant of Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Martin, P.S.

1979-01-01

We have characterized a methyl methanesulfonate sensitive mutant of the yeast Saccharomyces cerevisiae in order to learn more about DNA repair and mutagenesis in this organism. The mutation, designated mms3-1, also confers sensitivity to ultraviolet light and to ethyl methanesulfonate in both haploids and homozygous diploids. Its effect on γ-ray sensitivity, however, is a function of the ploidy of the cell and its effect on induced mutation is a function of both the ploidy of the cell and the nature of the inducing agent. Our major findings are discussed. Our data indicate that: (1) Saccharomyces cerevisiae has an error prone pathway for the repair of uv damage controlled by the MMS3 gene product operating in and only in, and possibly induced by conditions present only in, a/α diploids; (2) in diploids, at least, there exists at least one step in the error prone repair of uv induced damage which is different from a step in the error prone repair of EMS induced damage; (3) a/α mms3-1/mms3-1 diploids may be defective in a step common to the repair of mutagenic lesions following uv irradiation and lethal lesions following γ irradiation; and (4) there are steps in the repair of MMS induced lethal damage that are different from steps in the repair of EMS induced lethal damage

High-efficiency genome editing and allele replacement in prototrophic and wild strains of Saccharomyces.

Science.gov (United States)

Alexander, William G; Doering, Drew T; Hittinger, Chris Todd

2014-11-01

Current genome editing techniques available for Saccharomyces yeast species rely on auxotrophic markers, limiting their use in wild and industrial strains and species. Taking advantage of the ancient loss of thymidine kinase in the fungal kingdom, we have developed the herpes simplex virus thymidine kinase gene as a selectable and counterselectable marker that forms the core of novel genome engineering tools called the H: aploid E: ngineering and R: eplacement P: rotocol (HERP) cassettes. Here we show that these cassettes allow a researcher to rapidly generate heterogeneous populations of cells with thousands of independent chromosomal allele replacements using mixed PCR products. We further show that the high efficiency of this approach enables the simultaneous replacement of both alleles in diploid cells. Using these new techniques, many of the most powerful yeast genetic manipulation strategies are now available in wild, industrial, and other prototrophic strains from across the diverse Saccharomyces genus. Copyright © 2014 by the Genetics Society of America.

Biosynthesis of a hypermodified nucleotide in Saccharomyces carlsbergensis 17S and HeLa-cell 18S ribosomal ribonucleic acid.

Science.gov (United States)

Brand, R C; Klootwijk, J; Planta, R J; Maden, B E

1978-01-01

The biosynthesis of a hypermodified nucleotide, similar to or identical with 3-(3-amino-3-carboxypropyl)-1-methylpseudouridine monophosphate, present in Saccharomyces carlsbergensis 17S and HeLa-cell 18S rRNA, was investigated with respect to the sequence of reactions required for synthesis and their timing in ribosome maturation. In both yeast and HeLa cells methylation precedes attachment of the 3-amino-3-carboxypropyl group. In yeast the methylated precursor nucleotide was tentatively characterized as 1-methylpseudouridine. This precursor nucleotide was demonstrated in both 37S and most of the cytoplasmic 18S pre-rRNA (rRNA precursor) molecules. The synthesis of the hypermodified nucleotide is completed just before the final cleavage of 18S pre-rRNA to give 17S rRNA, so that the final addition of the 3-amino-3-carboxypropyl group is a cytoplasmic event. Comparable experiments with HeLa cells indicated that formation of 1-methylpseudouridine occurs at the level of 45S RNA and addition of the 3-amino-3-carboxypropyl group occurs in the cytoplasm on newly synthesized 18S RNA.

Xylose isomerase improves growth and ethanol production rates from biomass sugars for both Saccharomyces pastorianus and Saccharomyces cerevisiae.

Science.gov (United States)

Miller, Kristen P; Gowtham, Yogender Kumar; Henson, J Michael; Harcum, Sarah W

2012-01-01

The demand for biofuel ethanol made from clean, renewable nonfood sources is growing. Cellulosic biomass, such as switch grass (Panicum virgatum L.), is an alternative feedstock for ethanol production; however, cellulosic feedstock hydrolysates contain high levels of xylose, which needs to be converted to ethanol to meet economic feasibility. In this study, the effects of xylose isomerase on cell growth and ethanol production from biomass sugars representative of switch grass were investigated using low cell density cultures. The lager yeast species Saccharomyces pastorianus was grown with immobilized xylose isomerase in the fermentation step to determine the impact of the glucose and xylose concentrations on the ethanol production rates. Ethanol production rates were improved due to xylose isomerase; however, the positive effect was not due solely to the conversion of xylose to xylulose. Xylose isomerase also has glucose isomerase activity, so to better understand the impact of the xylose isomerase on S. pastorianus, growth and ethanol production were examined in cultures provided fructose as the sole carbon. It was observed that growth and ethanol production rates were higher for the fructose cultures with xylose isomerase even in the absence of xylose. To determine whether the positive effects of xylose isomerase extended to other yeast species, a side-by-side comparison of S. pastorianus and Saccharomyces cerevisiae was conducted. These comparisons demonstrated that the xylose isomerase increased ethanol productivity for both the yeast species by increasing the glucose consumption rate. These results suggest that xylose isomerase can contribute to improved ethanol productivity, even without significant xylose conversion. Copyright © 2012 American Institute of Chemical Engineers (AIChE).

1H High Resolution Magic-Angle Coil Spinning (HR-MACS µNMR Metabolic Profiling of whole Saccharomyces cervisiae cells: A Demonstrative Study

Directory of Open Access Journals (Sweden)

Alan eWong

2014-06-01

Full Text Available The low sensitivity of Nuclear Magnetic Resonance (NMR is its prime shortcoming compared to other analytical methods for metabolomic studies. It relies on large sample volume (30–50 µl for HR-MAS for rich metabolic profiling, hindering high-throughput screening especially when the sample requires a labor-intensive preparation or is a sacred specimen. This is indeed the case for some living organisms. This study evaluates a 1H HR-MAS approach for metabolic profiling of small volume (250 nl whole bacterial cells, Saccharomyces cervisiae, using an emerging micro-NMR technology: high-resolution magic-angle coil spinning (HR-MACS. As a demonstrative study for whole cells, we perform two independent metabolomics studies identifying the significant metabolites associated with osmotic stress and aging.

Saccharomyces cerevisiae and non-Saccharomyces yeasts in grape varieties of the São Francisco Valley

Directory of Open Access Journals (Sweden)

Camila M.P.B.S. de Ponzzes-Gomes

2014-06-01

Full Text Available The aims of this work was to characterise indigenous Saccharomyces cerevisiae strains in the naturally fermented juice of grape varieties Cabernet Sauvignon, Grenache, Tempranillo, Sauvignon Blanc and Verdejo used in the São Francisco River Valley, northeastern Brazil. In this study, 155 S. cerevisiae and 60 non-Saccharomyces yeasts were isolated and identified using physiological tests and sequencing of the D1/D2 domains of the large subunit of the rRNA gene. Among the non-Saccharomyces species, Rhodotorula mucilaginosa was the most common species, followed by Pichia kudriavzevii, Candida parapsilosis, Meyerozyma guilliermondii, Wickerhamomyces anomalus, Kloeckera apis, P. manshurica, C. orthopsilosis and C. zemplinina. The population counts of these yeasts ranged among 1.0 to 19 x 10(5 cfu/mL. A total of 155 isolates of S. cerevisiae were compared by mitochondrial DNA restriction analysis, and five molecular mitochondrial DNA restriction profiles were detected. Indigenous strains of S. cerevisiae isolated from grapes of the São Francisco Valley can be further tested as potential starters for wine production.

Gains and Losses of Transcription Factor Binding Sites in Saccharomyces cerevisiae and Saccharomyces paradoxus

Science.gov (United States)

Schaefke, Bernhard; Wang, Tzi-Yuan; Wang, Chuen-Yi; Li, Wen-Hsiung

2015-01-01

Gene expression evolution occurs through changes in cis- or trans-regulatory elements or both. Interactions between transcription factors (TFs) and their binding sites (TFBSs) constitute one of the most important points where these two regulatory components intersect. In this study, we investigated the evolution of TFBSs in the promoter regions of different Saccharomyces strains and species. We divided the promoter of a gene into the proximal region and the distal region, which are defined, respectively, as the 200-bp region upstream of the transcription starting site and as the 200-bp region upstream of the proximal region. We found that the predicted TFBSs in the proximal promoter regions tend to be evolutionarily more conserved than those in the distal promoter regions. Additionally, Saccharomyces cerevisiae strains used in the fermentation of alcoholic drinks have experienced more TFBS losses than gains compared with strains from other environments (wild strains, laboratory strains, and clinical strains). We also showed that differences in TFBSs correlate with the cis component of gene expression evolution between species (comparing S. cerevisiae and its sister species Saccharomyces paradoxus) and within species (comparing two closely related S. cerevisiae strains). PMID:26220934

Effects of furfural on the respiratory metabolism of Saccharomyces cerevisiae in glucose-limited chemostats,

OpenAIRE

Sarvari Horvath, I; Franzén, C J; Taherzadeh, M J; Niklasson, C; Lidén, Gunnar

2003-01-01

Effects of furfural on the aerobic metabolism of the yeast Saccharomyces cerevisiae were studied by performing chemostat experiments, and the kinetics of furfural conversion was analyzed by performing dynamic experiments. Furfural, an important inhibitor present in lignocellulosic hydrolysates, was shown to have an inhibitory effect on yeast cells growing respiratively which was much greater than the inhibitory effect previously observed for anaerobically growing yeast cells. The residual fur...

Metabolic Engineering of Probiotic Saccharomyces boulardii

OpenAIRE

Liu, Jing-Jing; Kong, In Iok; Zhang, Guo-Chang; Jayakody, Lahiru N.; Kim, Heejin; Xia, Peng-Fei; Kwak, Suryang; Sung, Bong Hyun; Sohn, Jung-Hoon; Walukiewicz, Hanna E.; Rao, Christopher V.; Jin, Yong-Su

2016-01-01

Saccharomyces boulardii is a probiotic yeast that has been used for promoting gut health as well as preventing diarrheal diseases. This yeast not only exhibits beneficial phenotypes for gut health but also can stay longer in the gut than Saccharomyces cerevisiae. Therefore, S. boulardii is an attractive host for metabolic engineering to produce biomolecules of interest in the gut. However, the lack of auxotrophic strains with defined genetic backgrounds has hampered the use of this strain for...

Use of INAA to study the interaction between Se and Te in cells of Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Czauderna, M.; Turska, M.; Sierokowska, S.; Smolinski, S.

1996-01-01

The differences in the effects of inorganic Se (IV and VI) compounds and seleno-cystine [(CySe) 2 ] on the Te (as Na 2 TeO 3 ) uptake by the yeast, Saccharomyces cerevisiae, has been studied. Se, Te, Ag, Zn, Fe and Co contents of the cells were measured by instrumental neutron activation analysis. For the determination of the Ag content, the monostandard method was applied as the analytical method. The contents of other elements were determined by comparison with standards having similar amounts of the determined element as the sample. Results obtained show that an antagonist interaction occurs between SeO 2 and Te. There was a significant increase in the concentration of Se and Te when the yeast was incubated in the medium containing (CySe) 2 and Te. (CySe) 2 markedly increased the Ag content of cells, especially within the first 8 h of incubation. The low level of SeO 2 in the medium are the exterior factor which produce an observable increase of the Ag concentration in the cells. The higher level of SeO 2 in the medium causes a long-term marked increase in the Ag content of the cells. The uptake yield of Ag also increased in the presence of (NH 4 ) 2 SeO 4 in the medium. The Te supply produced a significant enhancement in the Ag content of the cells during the initial 8 h of incubation. The presence of Se and/or Te in the medium causes change in the intracellular Zn, Fe and Co levels. (author)

Sterol synthesis and cell size distribution under oscillatory growth conditions in Saccharomyces cerevisiae scale-down cultivations.

Science.gov (United States)

Marbà-Ardébol, Anna-Maria; Bockisch, Anika; Neubauer, Peter; Junne, Stefan

2018-02-01

Physiological responses of yeast to oscillatory environments as they appear in the liquid phase in large-scale bioreactors have been the subject of past studies. So far, however, the impact on the sterol content and intracellular regulation remains to be investigated. Since oxygen is a cofactor in several reaction steps within sterol metabolism, changes in oxygen availability, as occurs in production-scale aerated bioreactors, might have an influence on the regulation and incorporation of free sterols into the cell lipid layer. Therefore, sterol and fatty acid synthesis in two- and three-compartment scale-down Saccharomyces cerevisiae cultivation were studied and compared with typical values obtained in homogeneous lab-scale cultivations. While cells were exposed to oscillating substrate and oxygen availability in the scale-down cultivations, growth was reduced and accumulation of carboxylic acids was increased. Sterol synthesis was elevated to ergosterol at the same time. The higher fluxes led to increased concentrations of esterified sterols. The cells thus seem to utilize the increased availability of precursors to fill their sterol reservoirs; however, this seems to be limited in the three-compartment reactor cultivation due to a prolonged exposure to oxygen limitation. Besides, a larger heterogeneity within the single-cell size distribution was observed under oscillatory growth conditions with three-dimensional holographic microscopy. Hence the impact of gradients is also observable at the morphological level. The consideration of such a single-cell-based analysis provides useful information about the homogeneity of responses among the population. Copyright © 2017 John Wiley & Sons, Ltd.

Conceptualizing suffering and pain.

Science.gov (United States)

Bueno-Gómez, Noelia

2017-09-29

This article aims to contribute to a better conceptualization of pain and suffering by providing non-essential and non-naturalistic definitions of both phenomena. Contributions of classical evidence-based medicine, the humanistic turn in medicine, as well as the phenomenology and narrative theories of suffering and pain, together with certain conceptions of the person beyond them (the mind-body dichotomy, Cassel's idea of persons as "intact beings") are critically discussed with such purpose. A philosophical methodology is used, based on the review of existent literature on the topic and the argumentation in favor of what are found as better definitions of suffering and pain. Pain can be described in neurological terms but cognitive awareness, interpretation, behavioral dispositions, as well as cultural and educational factors have a decisive influence on pain perception. Suffering is proposed to be defined as an unpleasant or even anguishing experience, severely affecting a person at a psychophysical and existential level. Pain and suffering are considered unpleasant. However, the provided definitions neither include the idea that pain and suffering can attack and even destroy the self nor the idea that they can constructively expand the self; both perspectives can b e equally useful for managing pain and suffering, but they are not defining features of the same. Including the existential dimension in the definition of suffering highlights the relevance of suffering in life and its effect on one's own attachment to the world (including personal management, or the cultural and social influences which shape it). An understanding of pain and suffering life experiences is proposed, meaning that they are considered aspects of a person's life, and the self is the ever-changing sum of these (and other) experiences. The provided definitions will be useful to the identification of pain and suffering, to the discussion of how to relieve them, and to a better understanding

Higher-order structure of Saccharomyces cerevisiae chromatin

International Nuclear Information System (INIS)

Lowary, P.T.; Widom, J.

1989-01-01

We have developed a method for partially purifying chromatin from Saccharomyces cerevisiae (baker's yeast) to a level suitable for studies of its higher-order folding. This has required the use of yeast strains that are free of the ubiquitous yeast killer virus. Results from dynamic light scattering, electron microscopy, and x-ray diffraction show that the yeast chromatin undergoes a cation-dependent folding into 30-nm filaments that resemble those characteristic of higher-cell chromatin; moreover, the packing of nucleosomes within the yeast 30-nm filaments is similar to that of higher cells. These results imply that yeast has a protein or protein domain that serves the role of the histone H 1 found in higher cells; physical and genetic studies of the yeast activity could help elucidate the structure and function of H 1. Images of the yeast 30-nm filaments can be used to test crossed-linker models for 30-nm filament structure

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.

Physiology of inactivation of microbial cells by near-ultraviolet light: mode of action and application for the enrichment of mutants of Escherichia coli and saccharomyces cerevisiae

International Nuclear Information System (INIS)

Peters, J.

1976-01-01

The mode of action of near-ultraviolet (NUV) light was studied in Escherichia coli. NUV light (maximum emission at 365 nm) caused the photodestruction of ribonucleoside diphosphate (RDP) reductase activity in vivo. Evidence was presented for a model suggesting that the loss of RDP-reductase resulted in a metabolic state analogous to that produced during starvation for thymine. Some important properties of cells irradiated by NUV light, cell death, loss of the ability to support the replication of DNA phages and a delay in the onset of cell division in sublethally irradiated cells, were accounted for in terms of photoinactivation of RDP-reductase. Conditions were described under which NUV light was an effective counterselective agent for the enrichment of mutants of Escherichia coli and Saccharomyces cerevisiae

Growth-rate regulated genes have profound impact on interpretation of transcriptome profiling in Saccharomyces cerevisiae

DEFF Research Database (Denmark)

Regenberg, Birgitte; Grotkjær, Thomas; Winther, Ole

2006-01-01

Growth rate is central to the development of cells in all organisms. However, little is known about the impact of changing growth rates. We used continuous cultures to control growth rate and studied the transcriptional program of the model eukaryote Saccharomyces cerevisiae, with generation time...

Division of labour in the yeast: Saccharomyces cerevisiae.

Science.gov (United States)

Wloch-Salamon, Dominika M; Fisher, Roberta M; Regenberg, Birgitte

2017-10-01

Division of labour between different specialized cell types is a central part of how we describe complexity in multicellular organisms. However, it is increasingly being recognized that division of labour also plays an important role in the lives of predominantly unicellular organisms. Saccharomyces cerevisiae displays several phenotypes that could be considered a division of labour, including quiescence, apoptosis and biofilm formation, but they have not been explicitly treated as such. We discuss each of these examples, using a definition of division of labour that involves phenotypic variation between cells within a population, cooperation between cells performing different tasks and maximization of the inclusive fitness of all cells involved. We then propose future research directions and possible experimental tests using S. cerevisiae as a model organism for understanding the genetic mechanisms and selective pressures that can lead to the evolution of the very first stages of a division of labour. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Genetic effects of decay of fuel fission products in cells of yeast Saccharomyces cerevisial. Role of transmutations

International Nuclear Information System (INIS)

Shanshiashvili, T.A.; Gracheva, L.M.

1981-01-01

Lethal and mutagenic effects and the nature of mutations induced by 91 Y decay in cells of Saccharomyces cerevisial yeasts were studied. An inactivation probability was (9.6+-4.0)x10 -5 decaysup(-I) and mutation probability in ade 1, ade 2 genes was (0.65+-0.53)x10 -8 decaysup(-I). It is shown that 95% of the effect is caused by local transmutation aftereffects of the decay of the isotope in the cell, and only 5% - by β-radiation. It is also shown that 91 Y is one of the most effective physical matagens. Its mutagenic efficiency (M/1 nS) is the same as of 32 P, and 3.5 times higher than the mutagenic efficiency of γ-rays, and 8 times - than of neutrons with E=1.3 MeV. According to the results of the analysis of the nature of mutations, 91 Y is a nonspecific mutagen which induces mutations of different types. Among 4B analyzed ade 2 mutations there have been detected 146(35%) transitions AT→GC, 139(34%) transitions GC→AT, 64(16%) mutations of reading frame shift, 63 (15%) transversions and 1 deletion. The reasons for such significant genetic effect of 91 Y on the cell are discussed [ru

Mechanisms and Regulation of Mitotic Recombination in Saccharomyces cerevisiae

Science.gov (United States)

Symington, Lorraine S.; Rothstein, Rodney; Lisby, Michael

2014-01-01

Homology-dependent exchange of genetic information between DNA molecules has a profound impact on the maintenance of genome integrity by facilitating error-free DNA repair, replication, and chromosome segregation during cell division as well as programmed cell developmental events. This chapter will focus on homologous mitotic recombination in budding yeast Saccharomyces cerevisiae. However, there is an important link between mitotic and meiotic recombination (covered in the forthcoming chapter by Hunter et al. 2015) and many of the functions are evolutionarily conserved. Here we will discuss several models that have been proposed to explain the mechanism of mitotic recombination, the genes and proteins involved in various pathways, the genetic and physical assays used to discover and study these genes, and the roles of many of these proteins inside the cell. PMID:25381364

Probing the fungicidal property of CdS quantum dots on Saccharomyces cerevisiae and Candida utilis using MALDI-MS

Energy Technology Data Exchange (ETDEWEB)

Manikandan, Muthu; Wu, Hui-Fen, E-mail: hwu@faculty.nsysu.edu.tw [National Sun Yat-Sen University, Department of Chemistry (China)

2013-07-15

For the first time, we report the successful application of inhouse synthesized CdS quantum dots (QDs) with particle sizes between 1 and 7 nm exhibiting excellent fungicidal activity based on the interactions with Saccharomyces cerevisiae and Candida utilis. The growth curves and the growth rates of both fungi were established in the presence of three varying concentrations of CdS QDs. It was observed that the CdS QDs were highly inhibitory even at the lowest concentration of 10 mg/L used in this study, while the untreated control cells followed a normal growth pattern in the cases of both Saccharomyces and Candida. MALDI-MS was applied to substantiate the observations obtained by direct cell count method. It was observed that the trend observed in the case of Saccharomyces and Candida was well-represented in the MALDI-MS spectra. This study proposes a mechanism for the first time based on MALDI-MS results, that the CdS QDs interact with the extracellular polymeric substances (EPS) and remove small molecules from EPS layer; on the other hand, it was observed that CdS QDs at all concentrations lead to enrichment of protein signals in MALDI-MS. We have substantiated these results by quantifying the EPS in the control and treated cells and also using TEM to further confirm the results.

Probing the fungicidal property of CdS quantum dots on Saccharomyces cerevisiae and Candida utilis using MALDI-MS

International Nuclear Information System (INIS)

Manikandan, Muthu; Wu, Hui-Fen

2013-01-01

For the first time, we report the successful application of inhouse synthesized CdS quantum dots (QDs) with particle sizes between 1 and 7 nm exhibiting excellent fungicidal activity based on the interactions with Saccharomyces cerevisiae and Candida utilis. The growth curves and the growth rates of both fungi were established in the presence of three varying concentrations of CdS QDs. It was observed that the CdS QDs were highly inhibitory even at the lowest concentration of 10 mg/L used in this study, while the untreated control cells followed a normal growth pattern in the cases of both Saccharomyces and Candida. MALDI-MS was applied to substantiate the observations obtained by direct cell count method. It was observed that the trend observed in the case of Saccharomyces and Candida was well-represented in the MALDI-MS spectra. This study proposes a mechanism for the first time based on MALDI-MS results, that the CdS QDs interact with the extracellular polymeric substances (EPS) and remove small molecules from EPS layer; on the other hand, it was observed that CdS QDs at all concentrations lead to enrichment of protein signals in MALDI-MS. We have substantiated these results by quantifying the EPS in the control and treated cells and also using TEM to further confirm the results

Review of Saccharomyces boulardii as a treatment option in IBD

DEFF Research Database (Denmark)

Sivananthan, Kavitha; Petersen, Andreas Munk

2018-01-01

CONTEXT: Review of the yeast Saccharomyces boulardii as a treatment option for the inflammatory bowel diseases (IBD) ulcerative colitis and Crohn's disease. OBJECTIVE: IBD is caused by an inappropriate immune response to gut microbiota. Treatment options could therefore be prebiotics, probiotics......, antibiotics and/or fecal transplant. In this review, we have looked at the evidence for the yeast S. boulardii as a treatment option. MATERIAL AND METHODS: Searches in PubMed and the Cochrane Library with the MeSH words 'Saccharomyces boulardii AND IBD', 'Saccharomyces boulardii AND Inflammatory Bowel Disease....... Saccharomyces boulardii is, however, a plausible treatment option in the future, but more placebo-controlled clinical studies on both patients with ulcerative colitis and Crohn's disease are needed....

Diagnosing suffering: a perspective.

Science.gov (United States)

Cassell, E J

1999-10-05

The alleviation of suffering is crucial in all of medicine, especially in the care of the dying. Suffering cannot be treated unless it is recognized and diagnosed. Suffering involves some symptom or process that threatens the patient because of fear, the meaning of the symptom, and concerns about the future. The meanings and the fear are personal and individual, so that even if two patients have the same symptoms, their suffering would be different. The complex techniques and methods that physicians usually use to make a diagnosis, however, are aimed at the body rather than the person. The diagnosis of suffering is therefore often missed, even in severe illness and even when it stares physicians in the face. A high index of suspicion must be maintained in the presence of serious disease, and patients must be directly questioned. Concerns over the discomfort of listening to patients' severe distress are usually more than offset by the gratification that follows the intervention. Often, questioning and attentive listening, which take little time, are in themselves ameliorative. The information on which the assessment of suffering is based is subjective; this may pose difficulties for physicians, who tend to value objective findings more highly and see a conflict between the two kinds of information. Recent advances in understanding how physicians increase the utility of information and make inferences allow one to reliably use the subjective information on which the diagnosis and treatment of suffering depend. Knowing patients as individual persons well enough to understand the origin of their suffering and ultimately its best treatment requires methods of empathic attentiveness and nondiscursive thinking that can be learned and taught. The relief of suffering depends on physicians acquiring these skills.

Effect of long- and short-term exposure to laser light at 1070 nm on growth of Saccharomyces cerevisiae

DEFF Research Database (Denmark)

Aabo, Thomas; Perch-Nielsen, Ivan R.; Dam, Jeppe Seidelin

2010-01-01

The effect of a 1070-nm continuous and pulsed wave ytterbium fiber laser on the growth of Saccharomyces cerevisiae single cells is investigated over a time span of 4 to 5 h. The cells are subjected to optical traps consisting of two counterpropagating plane wave beams with a uniform flux along th...

Gains and Losses of Transcription Factor Binding Sites in Saccharomyces cerevisiae and Saccharomyces paradoxus.

Science.gov (United States)

Schaefke, Bernhard; Wang, Tzi-Yuan; Wang, Chuen-Yi; Li, Wen-Hsiung

2015-07-27

Gene expression evolution occurs through changes in cis- or trans-regulatory elements or both. Interactions between transcription factors (TFs) and their binding sites (TFBSs) constitute one of the most important points where these two regulatory components intersect. In this study, we investigated the evolution of TFBSs in the promoter regions of different Saccharomyces strains and species. We divided the promoter of a gene into the proximal region and the distal region, which are defined, respectively, as the 200-bp region upstream of the transcription starting site and as the 200-bp region upstream of the proximal region. We found that the predicted TFBSs in the proximal promoter regions tend to be evolutionarily more conserved than those in the distal promoter regions. Additionally, Saccharomyces cerevisiae strains used in the fermentation of alcoholic drinks have experienced more TFBS losses than gains compared with strains from other environments (wild strains, laboratory strains, and clinical strains). We also showed that differences in TFBSs correlate with the cis component of gene expression evolution between species (comparing S. cerevisiae and its sister species Saccharomyces paradoxus) and within species (comparing two closely related S. cerevisiae strains). © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Tolerance to winemaking stress conditions of Patagonian strains of Saccharomyces eubayanus and Saccharomyces uvarum.

Science.gov (United States)

Origone, A C; Del Mónaco, S M; Ávila, J R; González Flores, M; Rodríguez, M E; Lopes, C A

2017-08-01

Evaluating the winemaking stress tolerance of a set of both Saccharomyces eubayanus and Saccharomyces uvarum strains from diverse Patagonian habitats. Yeast strains growth was analysed under increasing ethanol concentrations; all of them were able to grow until 8% v/v ethanol. The effect of different temperature and pH conditions as well as at SO 2 and hexose concentrations was evaluated by means of a central composite experimental design. Only two S. uvarum strains (NPCC 1289 and 1321) were able to grow in most stress conditions. Kinetic parameters analysed (μ max and λ) were statistically affected by temperature, pH and SO 2 , but not influenced by sugar concentration. The obtained growth model was used for predicting optimal growth conditions for both strains: 20°C, 0% w/v SO 2 and pH 4·5. Strains from human-associated environments (chichas) presented the highest diversity in the response to different stress factors. Two S. uvarum strains from chichas demonstrated to be the most tolerant to winemaking conditions. This work evidenced the potential use of two S. uvarum yeast strains as starter cultures in wines fermented at low temperatures. Saccharomyces eubayanus was significantly affected by winemaking stress conditions, limiting its use in this industry. © 2017 The Society for Applied Microbiology.

An in vitro assay for (1-->6)-beta-D-glucan synthesis in Saccharomyces cerevisiae.

NARCIS (Netherlands)

Vink, E.; Rodriguez-Suarez, R.J.; Gerard-Vincent, M.; Ribas, J.C.; de Nobel, J.G.; van den Ende, H.; Duran, A.; Klis, F.M.; Bussey, H.

2004-01-01

(1 --> 6)-beta-D-glucan is a key cell wall component of Saccharomyces cerevisiae and Candida albicans. Many genes are known to affect the levels or structure of this glucan, but their roles and a molecular description of the synthesis of (1 --> 6)-beta-D-glucan remain to be established and a method

Factors affecting the palmitoyl-coenzyme A desaturase of Saccharomyces cerevisiae

Science.gov (United States)

Klein, H. P.; Volkmann, C. M.

1975-01-01

The activity and stability of the palmitoyl-coenzyme A (CoA) desaturase complex of Saccharomyces cerevisiae was influenced by several factors. Cells, grown nonaerobically and then incubated with glucose, either in air or under N2, showed a marked increase in desaturase activity. Cycloheximide, added during such incubations, prevented the increase in activity, suggesting de novo synthesis. The stability of the desaturase from cells grown nonaerobically was affected by subsequent treatment of the cells; enzyme from freshly harvested cells, or from cells that were then shaken under nitrogen, readily lost activity upon washing or during density gradient analysis, whereas aerated cells, in the presence or absence of glucose, yielded stable enzyme preparations. The loss of activity in nonaerobic preparations could be reversed by adding soluble supernatant from these homogenates and could be prevented by growing the cells in the presence of palmitoleic acid and ergosterol, but not with several other lipids tested.

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.

Saccharomyces boulardii improves intestinal cell restitution through activation of the α2β1 integrin collagen receptor.

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Alexandra Canonici

Full Text Available Intestinal epithelial cell damage is frequently seen in the mucosal lesions of inflammatory bowel diseases such as ulcerative colitis or Crohn's disease. Complete remission of these diseases requires both the cessation of inflammation and the migration of enterocytes to repair the damaged epithelium. Lyophilized Saccharomyces boulardii (Sb, Biocodex is a nonpathogenic yeast widely used as a therapeutic agent for the treatment and prevention of diarrhea and other gastrointestinal disorders. In this study, we determined whether Sb could accelerate enterocyte migration. Cell migration was determined in Sb force-fed C57BL6J mice and in an in vitro wound model. The impact on α2β1 integrin activity was assessed using adhesion assays and the analysis of α2β1 mediated signaling pathways both in vitro and in vivo. We demonstrated that Sb secretes compounds that enhance the migration of enterocytes independently of cell proliferation. This enhanced migration was associated with the ability of Sb to favor cell-extracellular matrix interaction. Indeed, the yeast activates α2β1 integrin collagen receptors. This leads to an increase in tyrosine phosphorylation of cytoplasmic molecules, including focal adhesion kinase and paxillin, involved in the integrin signaling pathway. These changes are associated with the reorganization of focal adhesion structures. In conclusion Sb secretes motogenic factors that enhance cell restitution through the dynamic regulation of α2β1 integrin activity. This could be of major importance in the development of novel therapies targeting diseases characterized by severe mucosal injury, such as inflammatory and infectious bowel diseases.

Biotechnology of non-Saccharomyces yeasts-the basidiomycetes.

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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

Improvement of lactic acid production in Saccharomyces cerevisiae by a deletion of ssb1.

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Lee, Jinsuk J; Crook, Nathan; Sun, Jie; Alper, Hal S

2016-01-01

Polylactic acid (PLA) is an important renewable polymer, but current processes for producing its precursor, lactic acid, suffer from process inefficiencies related to the use of bacterial hosts. Therefore, improving the capacity of Saccharomyces cerevisiae to produce lactic acid is a promising approach to improve industrial production of lactic acid. As one such improvement required, the lactic acid tolerance of yeast must be significantly increased. To enable improved tolerance, we employed an RNAi-mediated genome-wide expression knockdown approach as a means to rapidly identify potential genetic targets. In this approach, several gene knockdown targets were identified which confer increased acid tolerance to S. cerevisiae BY4741, of which knockdown of the ribosome-associated chaperone SSB1 conferred the highest increase (52%). This target was then transferred into a lactic acid-overproducing strain of S. cerevisiae CEN.PK in the form of a knockout and the resulting strain demonstrated up to 33% increased cell growth, 58% increased glucose consumption, and 60% increased L-lactic acid production. As SSB1 contains a close functional homolog SSB2 in yeast, this result was counterintuitive and may point to as-yet-undefined functional differences between SSB1 and SSB2 related to lactic acid production. The final strain produced over 50 g/L of lactic acid in under 60 h of fermentation.

Comportamento celular e resposta antioxidante diferenciados de Saccharomyces cerevisiae e de Saccharomyces chevalieri ao metavanadato de amónio Different cellular behaviour and antioxidant response of Saccharomyces cerevisiae and Saccharomyces chevalieri growing in presence of ammonium metavanadate

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R. Ferreira

2007-01-01

conditions. In the cellular environment of aerobic organisms naturally reactive oxygen species (ROS occurs as by-products of mitochondrial respiration. The higher reactivity of these chemical species could cause molecular damages that in several cases induce cellular death. In common physiological conditions or as response to oxidative stress, the cell can generate adapted responses which involve antioxidants mechanisms as glutathione reductase (GR; EC 1.6.4.2 and catalase T (CAT T; EC 1.11.1.6 and A (CAT A; EC 1.11.1.6 enzymes. Vanadium, a heavy metal present in several pesticides could generate ROS changing the intracellular redox state and cause deleterious effects in yeasts exposed to higher levels of this element. The main objective of this work was to compare the effects of ammonium metavanadate (NH4VO3, a pentavalent salt of vanadium on cellular viability and GR, CAT T and CAT A activities of wine yeast Saccharomyces cerevisiae UE-ME3 and Saccharomyces chevalieri UE-ME1. The results obtained show that S. chevalieri UE-ME1 has lower tolerance to NH4VO3 than S. cerevisiae UE-ME3, since S. chevalieri cultures do not survive to concentration values of ammonium metavanadate higher than 7,5 mM, whereas S. cerevisiae cells are still viable in the presence of 75 mM. S. chevalieri has an enzymatic activity lower than S. cerevisiae, although for both yeast species NH4VO3 could behave as oxidative stress inductor, causing a significant decrease of GR activity (P<0,01 and a significant increase of CAT A activity (P<0,01. The results show also an increase of CAT T activity in both yeast species, which can be interpreted as a protective response to oxidative stress. Differences on response to amonium metavanadate by both species of Saccharomyces could be partially justified by more efficient antioxidant systems in S. cerevisiae UE-ME3.

Energy-dependent effects of resveratrol in Saccharomyces cerevisiae.

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Madrigal-Perez, Luis Alberto; Canizal-Garcia, Melina; González-Hernández, Juan Carlos; Reynoso-Camacho, Rosalia; Nava, Gerardo M; Ramos-Gomez, Minerva

2016-06-01

The metabolic effects induced by resveratrol have been associated mainly with the consumption of high-calorie diets; however, its effects with standard or low-calorie diets remain unclear. To better understand the interactions between resveratrol and cellular energy levels, we used Saccharomyces cerevisiae as a model. Herein it is shown that resveratrol: (a) decreased cell viability in an energy-dependent manner; (b) lessening of cell viability occurred specifically when cells were under cellular respiration; and (c) inhibition of oxygen consumption in state 4 occurred at low and standard energy levels, whereas at high energy levels oxygen consumption was promoted. These findings indicate that the effects of resveratrol are dependent on the cellular energy status and linked to metabolic respiration. Importantly, our study also revealed that S. cerevisiae is a suitable and useful model to elucidate the molecular targets of resveratrol under different nutritional statuses. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Caffeine enhancement of radiation killing in different strains of Saccharomyces cerevisiae

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Hannan, M.A.; Nasim, A.

1977-01-01

Haploid and diploid wild type strains, and three classes of radiation-sensitive mutants of Saccharomyces cerrevisiae were tesed for enhancement of UV-inactivation by caffeine in growth medium. In addition the sensitizing effect of caffeine was studied in a haploid and a diploid wild type strain after gamma-irradiation. The drug sensitized the UV-irradiated cells of all strains except those reported to be only slightly UV-sensitive but highly sensitive to ionizing radiation. After gamma-irradiation, no coffeine-enhancement of killing was observed in stationary phase cells of either the haploid or the diploid strain. However, log-phase cells of both strains were partially sensitized. The results of both sets of experiments suggested that caffeine interferes with a recombinational repair occurring in cells in S or G2 phase. (orig.) [de

From mannan to bioethanol: cell surface co-display of β-mannanase and β-mannosidase on yeast Saccharomyces cerevisiae.

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Ishii, Jun; Okazaki, Fumiyoshi; Djohan, Apridah Cameliawati; Hara, Kiyotaka Y; Asai-Nakashima, Nanami; Teramura, Hiroshi; Andriani, Ade; Tominaga, Masahiro; Wakai, Satoshi; Kahar, Prihardi; Yopi; Prasetya, Bambang; Ogino, Chiaki; Kondo, Akihiko

2016-01-01

Mannans represent the largest hemicellulosic fraction in softwoods and also serve as carbohydrate stores in various plants. However, the utilization of mannans as sustainable resources has been less advanced in sustainable biofuel development. Based on a yeast cell surface-display technology that enables the immobilization of multiple enzymes on the yeast cell walls, we constructed a recombinant Saccharomyces cerevisiae strain that co-displays β-mannanase and β-mannosidase; this strain is expected to facilitate ethanol fermentation using mannan as a biomass source. Parental yeast S. cerevisiae assimilated mannose and glucose as monomeric sugars, producing ethanol from mannose. We constructed yeast strains that express tethered β-mannanase and β-mannosidase; co-display of the two enzymes on the cell surface was confirmed by immunofluorescence staining and enzyme activity assays. The constructed yeast cells successfully hydrolyzed 1,4-β-d-mannan and produced ethanol by assimilating the resulting mannose without external addition of enzymes. Furthermore, the constructed strain produced ethanol from 1,4-β-d-mannan continually during the third batch of repeated fermentation. Additionally, the constructed strain produced ethanol from ivory nut mannan; ethanol yield was improved by NaOH pretreatment of the substrate. We successfully displayed β-mannanase and β-mannosidase on the yeast cell surface. Our results clearly demonstrate the utility of the strain co-displaying β-mannanase and β-mannosidase for ethanol fermentation from mannan biomass. Thus, co-tethering β-mannanase and β-mannosidase on the yeast cell surface provides a powerful platform technology for yeast fermentation toward the production of bioethanol and other biochemicals from lignocellulosic materials containing mannan components.

Saccharomyces boulardii CNCM I-745 in different clinical conditions.

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Dinleyici, Ener Cagri; Kara, Ates; Ozen, Metehan; Vandenplas, Yvan

2014-11-01

Saccharomyces boulardii is a well-known probiotic worldwide, and there are numerous studies including experimental and clinical trials in children and adults by the use of S. boulardii. The objective of the present report is to provide an update on the evidence for the efficacy of S. boulardii CNCM I-745 in different clinical conditions. Saccharomyces boulardii is one of the best-studied probiotics in acute gastroenteritis (AGE) and is shown to be safe and to reduce the duration of diarrhea and hospitalization by about 1 day. Saccharomyces boulardii is one of the recommended probiotics for AGE in children by European Society of Paediatric Infectious Diseases and European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN). Saccharomyces boulardii is also a recommended probiotic for the prevention of antibiotic-associated diarrhea (AAD), and a recent study showed promising results for the treatment of AAD in children. There is insufficient evidence to recommend the long-term use of S. boulardii in patients with irritable bowel syndrome. Although some clinical studies showed positive effects of S. boulardii on inflammation, there is no clinical evidence that S. boulardii is useful in inflammatory bowel disease. Saccharomyces boulardii could be used in patients needing Helicobacter pylori eradication because the S. boulardii improves compliance, decreases the side effects and moderately increases the eradication rate. There are new promising results (improving feeding tolerance, shorten the course of hyperbilirubinemia), but we do still not recommend the routine use of S. boulardii in newborns. Saccharomyces boulardii CNCM I-745 is a good example for the statement that each probiotic needs to be taxonomically characterized and its efficacy and safety should be documented individually in different clinical settings.

Inheritance and organisation of the mitochondrial genome differ between two Saccharomyces yeasts

DEFF Research Database (Denmark)

Petersen, Randi Føns; Langkjær, Rikke Breinhold; Hvidtfeldt, J.

2002-01-01

Petite-positive Saccharomyces yeasts can be roughly divided into the sensu stricto, including Saccharomyces cerevisiae, and sensu lato group, including Saccharomyces castellii; the latter was recently studied for transmission and the organisation of its mitochondrial genome. S. castellii mitochon......Petite-positive Saccharomyces yeasts can be roughly divided into the sensu stricto, including Saccharomyces cerevisiae, and sensu lato group, including Saccharomyces castellii; the latter was recently studied for transmission and the organisation of its mitochondrial genome. S. castellii...... mitochondrial molecules (mtDNA) carrying point mutations, which confer antibiotic resistance, behaved in genetic crosses as the corresponding point mutants of S. cerevisiae. While S. castellii generated spontaneous petite mutants in a similar way as S. cerevisiae, the petites exhibited a different inheritance...... pattern. In crosses with the wild type strains a majority of S. castellii petites was neutral, and the suppressivity in suppressive petites was never over 50%. The two yeasts also differ in organisation of their mtDNA molecules. The 25,753 bp sequence of S. castellii mtDNA was determined and the coding...

Saccharomyces cerevisiae var. boulardii fungemia following probiotic treatment

OpenAIRE

Appel-da-Silva, Marcelo C.; Narvaez, Gabriel A.; Perez, Leandro R.R.; Drehmer, Laura; Lewgoy, Jairo

2017-01-01

Probiotics are commonly prescribed as an adjuvant in the treatment of antibiotic-associated diarrhea caused by Clostridium difficile. We report the case of an immunocompromised 73-year-old patient on chemotherapy who developed Saccharomyces cerevisiae var. boulardii fungemia in a central venous catheter during treatment of antibiotic-associated pseudomembranous colitis with the probiotic Saccharomyces cerevisiae var. boulardii. Fungemia was resolved after interruption of probiotic administrat...

Saccharomyces boulardii expresses neuraminidase activity selective for α2,3-linked sialic acid that decreases Helicobacter pylori adhesion to host cells.

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Sakarya, Serhan; Gunay, Necati

2014-10-01

Helicobacter pylori is a major causative agent of gastritis and peptic ulcer disease and is an established risk factor for gastric malignancy. Antibiotic combination therapy can eradicate H. pylori. As these same regimens can evoke adverse effects and resistance, new alternative therapies or adjunctive treatments are needed. A probiotic approach may provide a novel strategy for H. pylori treatment. In the current study, two probiotic bacteria, Lactobacillus acidophilus and Lactobacillus reuteri, and a probiotic yeast, Saccharomyces boulardii, were evaluated for their ability to influence H. pylori viability, adherence to gastric and duodenal cells, as well as the effect of S. boulardii on cell surface expression of sialic acid. Our results indicate that S. boulardii contains neuraminidase activity selective for α(2-3)-linked sialic acid. This neuraminidase activity removes surface α(2-3)-linked sialic acid, the ligand for the sialic acid-binding H. pylori adhesin, which in turn, inhibits H. pylori adherence to duodenal epithelial cells. © 2014 APMIS. Published by John Wiley & Sons Ltd.

Brazilian propolis protects Saccharomyces cerevisiae cells against oxidative stress

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Rafael A. de Sá

2013-09-01

Full Text Available Propolis is a natural product widely used for humans. Due to its complex composition, a number of applications (antimicrobial, antiinflammatory, anesthetic, cytostatic and antioxidant have been attributed to this substance. Using Saccharomyces cerevisiae as a eukaryotic model we investigated the mechanisms underlying the antioxidant effect of propolis from Guarapari against oxidative stress. Submitting a wild type (BY4741 and antioxidant deficient strains (ctt1∆, sod1∆, gsh1∆, gtt1∆ and gtt2∆ either to 15 mM menadione or to 2 mM hydrogen peroxide during 60 min, we observed that all strains, except the mutant sod1∆, acquired tolerance when previously treated with 25 µg/mL of alcoholic propolis extract. Such a treatment reduced the levels of ROS generation and of lipid peroxidation, after oxidative stress. The increase in Cu/Zn-Sod activity by propolis suggests that the protection might be acting synergistically with Cu/Zn-Sod.

Ethanol from hydrolyzed whey permeate using Saccharomyces cerevisiae in a membrane recycle bioreactor

Energy Technology Data Exchange (ETDEWEB)

Mehaia, M A [King Saud Univ., Buriedah (Saudi Arabia). Dairy Technology Lab.; Cheryan, M [Illinois Univ., Urbana, IL (USA). Agricultural Bioprocess Lab.

1990-02-13

A diauxic fermentation was observed during batch fermentation of enzyme-hydrolyzed whey permeate to ethanol by Saccharomyces cerevisiae. Glucose was consumed before and much faster than galactose. In the continuous membrane recycle bioreactor (MRB), sugar utilization was a function of dilution rate and concentration of sugars. At a cell concentration of 160 kg/m{sup 3}, optimum productivity was 31 kg/(m{sup 3}.h) at ethanol concentration of 65 kg/m{sup 3}. Low levels of acetate (0.05-0.1 M) reduced cell growth during continuous fermentation, but also reduced galactose utilization. (orig.).

Non-Saccharomyces in Wine: Effect Upon Oenococcus oeni and Malolactic Fermentation

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Aitor Balmaseda

2018-03-01

Full Text Available This work is a short review of the interactions between oenological yeasts and lactic acid bacteria (LAB, especially Oenococcus oeni, the main species carrying out the malolactic fermentation (MLF. The emphasis has been placed on non-Saccharomyces effects due to their recent increased interest in winemaking. Those interactions are variable, ranging from inhibitory, to neutral and stimulatory and are mediated by some known compounds, which will be discussed. One phenomena responsible of inhibitory interactions is the media exhaustion by yeasts, and particularly a decrease in L-malic acid by some non-Saccharomyces. Clearly ethanol is the main inhibitory compound of LAB produced by S. cerevisiae, but non-Saccharomyces can be used to decrease it. Sulfur dioxide and medium chain fatty acids (MCFAs produced by yeasts can exhibit inhibitory effect upon LAB or even result lethal. Interestingly mixed fermentations with non-Saccharomyces present less MCFA concentration. Among organic acids derived as result of yeast metabolism, succinic acid seems to be the most related with MLF inhibition. Several protein factors produced by S. cerevisiae inhibiting O. oeni have been described, but they have not been studied in non-Saccharomyces. According to the stimulatory effects, the use of non-Saccharomyces can increase the concentration of favorable mediators such as citric acid, pyruvic acid, or other compounds derived of yeast autolysis such as peptides, glucans, or mannoproteins. The emergence of non-Saccharomyces in winemaking present a new scenario in which MLF has to take place. For this reason, new tools and approaches should be explored to better understand this new winemaking context.

Non-Saccharomyces in Wine: Effect Upon Oenococcus oeni and Malolactic Fermentation.

Science.gov (United States)

Balmaseda, Aitor; Bordons, Albert; Reguant, Cristina; Bautista-Gallego, Joaquín

2018-01-01

This work is a short review of the interactions between oenological yeasts and lactic acid bacteria (LAB), especially Oenococcus oeni , the main species carrying out the malolactic fermentation (MLF). The emphasis has been placed on non- Saccharomyces effects due to their recent increased interest in winemaking. Those interactions are variable, ranging from inhibitory, to neutral and stimulatory and are mediated by some known compounds, which will be discussed. One phenomena responsible of inhibitory interactions is the media exhaustion by yeasts, and particularly a decrease in L-malic acid by some non- Saccharomyces . Clearly ethanol is the main inhibitory compound of LAB produced by S. cerevisiae , but non- Saccharomyces can be used to decrease it. Sulfur dioxide and medium chain fatty acids (MCFAs) produced by yeasts can exhibit inhibitory effect upon LAB or even result lethal. Interestingly mixed fermentations with non- Saccharomyces present less MCFA concentration. Among organic acids derived as result of yeast metabolism, succinic acid seems to be the most related with MLF inhibition. Several protein factors produced by S. cerevisiae inhibiting O. oeni have been described, but they have not been studied in non- Saccharomyces . According to the stimulatory effects, the use of non- Saccharomyces can increase the concentration of favorable mediators such as citric acid, pyruvic acid, or other compounds derived of yeast autolysis such as peptides, glucans, or mannoproteins. The emergence of non- Saccharomyces in winemaking present a new scenario in which MLF has to take place. For this reason, new tools and approaches should be explored to better understand this new winemaking context.

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...

Sugar and Glycerol Transport in Saccharomyces cerevisiae.

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Bisson, Linda F; Fan, Qingwen; Walker, Gordon A

2016-01-01

In Saccharomyces cerevisiae the process of transport of sugar substrates into the cell comprises a complex network of transporters and interacting regulatory mechanisms. Members of the large family of hexose (HXT) transporters display uptake efficiencies consistent with their environmental expression and play physiological roles in addition to feeding the glycolytic pathway. Multiple glucose-inducing and glucose-independent mechanisms serve to regulate expression of the sugar transporters in yeast assuring that expression levels and transporter activity are coordinated with cellular metabolism and energy needs. The expression of sugar transport activity is modulated by other nutritional and environmental factors that may override glucose-generated signals. Transporter expression and activity is regulated transcriptionally, post-transcriptionally and post-translationally. Recent studies have expanded upon this suite of regulatory mechanisms to include transcriptional expression fine tuning mediated by antisense RNA and prion-based regulation of transcription. Much remains to be learned about cell biology from the continued analysis of this dynamic process of substrate acquisition.

Social wasps are a Saccharomyces mating nest.

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Stefanini, Irene; Dapporto, Leonardo; Berná, Luisa; Polsinelli, Mario; Turillazzi, Stefano; Cavalieri, Duccio

2016-02-23

The reproductive ecology of Saccharomyces cerevisiae is still largely unknown. Recent evidence of interspecific hybridization, high levels of strain heterozygosity, and prion transmission suggest that outbreeding occurs frequently in yeasts. Nevertheless, the place where yeasts mate and recombine in the wild has not been identified. We found that the intestine of social wasps hosts highly outbred S. cerevisiae strains as well as a rare S. cerevisiae×S. paradoxus hybrid. We show that the intestine of Polistes dominula social wasps favors the mating of S. cerevisiae strains among themselves and with S. paradoxus cells by providing a succession of environmental conditions prompting cell sporulation and spores germination. In addition, we prove that heterospecific mating is the only option for European S. paradoxus strains to survive in the gut. Taken together, these findings unveil the best hidden secret of yeast ecology, introducing the insect gut as an environmental alcove in which crosses occur, maintaining and generating the diversity of the ascomycetes.

Identification of autophagy genes participating in zinc-induced necrotic cell death in Saccharomyces cerevisiae.

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Dziedzic, Slawomir A; Caplan, Allan B

2011-05-01

Eukaryotes use a common set of genes to perform two mechanistically similar autophagic processes. Bulk autophagy harvests proteins nonselectively and reuses their constitutents when nutrients are scarce. In contrast, different forms of selective autophagy target protein aggregates or damaged organelles that threaten to interfere with growth. Yeast uses one form of selective autophagy, called cytoplasm-to-vacuole targeting (Cvt), to engulf two vacuolar enzymes in Cvt vesicles ("CVT-somes") within which they are transported to vacuoles for maturation. While both are dispensable normally, bulk and selective autophagy help sustain life under stressful conditions. Consistent with this view, knocking out several genes participating in Cvt and specialized autophagic pathways heightened the sensitivity of Saccharomyces cerevisiae to inhibitory levels of Zn(2+). The loss of other autophagic genes, and genes responsible for apoptotic cell death, had no such effect. Unexpectedly, the loss of members of a third set of autophagy genes heightened cellular resistance to zinc as if they encoded proteins that actively contributed to zinc-induced cell death. Further studies showed that both sensitive and resistant strains accumulated similar amounts of H2O2 during zinc treatments, but that more sensitive strains showed signs of necrosis sooner. Although zinc lethality depended on autophagic proteins, studies with several reporter genes failed to reveal increased autophagic activity. In fact, microscopy analysis indicated that Zn(2+) partially inhibited fusion of Cvt vesicles with vacuoles. Further studies into how the loss of autophagic processes suppressed necrosis in yeast might reveal whether a similar process could occur in plants and animals.

Induction of mitotic recombination by UV and diepoxybutane and its enhancement by hydroxyurea in Saccharomyces cerevisae

Energy Technology Data Exchange (ETDEWEB)

Zaborowska, D.; Swietlinska, Z.; Zuk, J. (Polska Akademia Nauk, Warsaw. Inst. Biochemii i Biofizyki)

1983-04-01

Mitotic inter- and intra-genic recombination was induced by UV-irradiation and treatment with diepoxybutane (DEB) in 2 heteroallelic diploid strains of Saccharomyces cerevisiae SBTD and D7. Induction of the events tested was strongly potentiated by plating of mutagen-treated cells on growth media containing 0.03 M hydroxyurea (HU).

The Paradox of Modern Suffering

DEFF Research Database (Denmark)

Dræby, Anders

The Paradox of Suffering in modern western Culture In non-western cultures and pre-modern western cultures suffering is considered the normal state of life. Corrispondingly the suffering of oneself and that of other people form a central focus to most religions, their practices and philosophies...

Functional expression of rat VPAC1 receptor in Saccharomyces cerevisiae

DEFF Research Database (Denmark)

Hansen, M.K.; Tams, J.W.; Fahrenkrug, Jan

1999-01-01

G protein-coupled receptor; heterologous expression; membrane protein; Saccharomyces cerevisiae, vasoactive intestinal polypeptide; yeast mating factor-pre-pro *Ga-leader peptide......G protein-coupled receptor; heterologous expression; membrane protein; Saccharomyces cerevisiae, vasoactive intestinal polypeptide; yeast mating factor-pre-pro *Ga-leader peptide...

Effects of low X-ray doses in Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Jordan, A.; Laskowski, W.

1987-01-01

Three strains of Saccharomyces cerevisiae with different capacities for repair of radiation damage (RAD, rad18, and rad52) have been tested for their colony forming ability (CFA) and growth rates after application of small X-ray doses from 3.8 mGy to 40 Gy. There was no reproducible increase in CFA observable after application of doses between 3.8 mGy and 4.7 Gy.X-ray doses of 40 Gy causing an inactivation of CFA from 90% to 50%, depending on the repair capacity of the strains used, caused a reduced increase in optical density during 2 h buffer treatment in comparison to unirradiated cells. This reduction however, is reversible as soon as the cells are transferred into nutrient medium. One hour after transfer into growh medium the portions of cells with large buds (Gs and M phase) and cells with small buds (S phase) are drastically different in irradiated cells from those obtained in unirradiated cells. The time necessary for separation of mother and daughter cells is prolonged by X-ray irradiation and the formation of new buds is retarded. (orig.)

Influence the oxidant action of selenium in radiosensitivity induction and cell death in yeast Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Porto, Barbara Abranches de Araujo

2012-01-01

Ionizing radiations are from both natural sources such as from anthropogenic sources. Recently, radiotherapy has emerged as one of the most common therapies against cancer. Co-60 irradiators (cobalt-60 linear accelerators) are used to treat of malignant tumors routinely in hospitals around the world. Exposure to ionizing radiation can induce changes in cellular macromolecules and affect its functions, because they cause radiolysis of the water molecule generating reactive oxygen species, which can cause damage to virtually all organelles and cell components known as oxidative damage that can culminate in oxidative stress. Oxidative stress is a situation in which the balance between oxidants and antioxidants is broken resulting in excessive production of reactive species, it is not accompanied by the increase in antioxidant capacity, making it impossible to neutralize them. Selenium is a micronutrient considered as antioxidant, antiinflammatory, which could prevent cancer. Selenium in biological system exists as seleno proteins. Nowadays, 25 human seleno proteins have been identified, including glutathione peroxidase, an antioxidant enzyme. Yeasts have the ability to incorporate various metals such as iron, cadmium, zinc and selenium, as well as all biological organisms. The yeast Saccharomyces cerevisiae, unlike mammalian cells is devoid of seleno proteins, being considered as a practical model for studies on the toxicity of selenium, without any interference from the metabolism of seleno proteins. Moreover, yeast cells proliferate through the fermentation, the microbial equivalent of aerobic glycolysis in mammals and the process is also used by tumors. Several reports show that the pro-oxidante effects and induced toxic selenium compounds occur at lower doses and in malignant cells compared with benign cells. Therefore selenium giving a great therapeutic potential in cancer treatment .Our objective was to determine whether selenium is capable to sensitize yeasts

Tight Coupling of Metabolic Oscillations and Intracellular Water Dynamics in Saccharomyces cerevisiae

DEFF Research Database (Denmark)

Thoke, Henrik Seir; Tobiesen, Asger; Brewer, Jonathan R.

2015-01-01

We detected very strong coupling between the oscillating concentration of ATP and the dynamics of intracellular water during glycolysis in Saccharomyces cerevisiae. Our results indicate that: i) dipolar relaxation of intracellular water is heterogeneous within the cell and different from dilute...... conditions, ii) water dipolar relaxation oscillates with glycolysis and in phase with ATP concentration, iii) this phenomenon is scale-invariant from the subcellular to the ensemble of synchronized cells and, iv) the periodicity of both glycolytic oscillations and dipolar relaxation are equally affected by D...

Improvement of Lead Tolerance of Saccharomyces cerevisiae by Random Mutagenesis of Transcription Regulator SPT3.

Science.gov (United States)

Zhu, Liying; Gao, Shan; Zhang, Hongman; Huang, He; Jiang, Ling

2018-01-01

Bioremediation of heavy metal pollution with biomaterials such as bacteria and fungi usually suffer from limitations because of microbial sensitivity to high concentration of heavy metals. Herein, we adopted a novel random mutagenesis technique called RAISE to manipulate the transcription regulator SPT3 of Saccharomyces cerevisiae to improve cell lead tolerance. The best strain Mutant VI was selected from the random mutagenesis libraries on account of the growth performance, with higher specific growth rate than the control strain (0.068 vs. 0.040 h -1 ) at lead concentration as high as 1.8 g/L. Combined with the transcriptome analysis of S. cerevisiae, expressing the SPT3 protein was performed to make better sense of the global regulatory effects of SPT3. The data analysis revealed that 57 of S. cerevisiae genes were induced and 113 genes were suppressed, ranging from those for trehalose synthesis, carbon metabolism, and nucleotide synthesis to lead resistance. Especially, the accumulation of intracellular trehalose in S. cerevisiae under certain conditions of stress is considered important to lead resistance. The above results represented that SPT3 was acted as global transcription regulator in the exponential phase of strain and accordingly improved heavy metal tolerance in the heterologous host S. cerevisiae. The present study provides a route to complex phenotypes that are not readily accessible by traditional methods.

Adaptive response of yeast cultures (Saccharomyces Cerevisiae) exposed to low dose of gamma radiation

International Nuclear Information System (INIS)

Kulcsar, Agnes; Savu, D.; Petcu, I.; Gherasim, Raluca

2003-01-01

The present study was planned as follows: (i) setting up of standard experimental conditions for investigation of radio-induced adaptive response in lower Eucaryotes; (ii) developing of procedures for synchronizing Saccharomyces cerevisiae X 310 D cell cultures and cell cycle stages monitoring; (iii) investigation of gamma (Co-60) and UV irradiation effects on the viability of synchronized and non-synchronized cell cultures of Saccharomyces cerevisiae; the effects were correlated with the cell density and cell cycle stage; (iv) study of the adaptive response induced by irradiation and setting up of the experimental conditions for which this response is optimized. The irradiations were performed by using a Co-60 with doses of 10 2 - 10 4 Gy and dose rates ranging from 2.2 x 10 2 Gy/h to 8.7 x 10 3 Gy/h. The study of radioinduced adaptive response was performed by applying a pre-irradiation treatment of 100-500 Gy, followed by challenge doses of 2-4 kGy delivered at different time intervals, ranging from 1 h to 4 h. The survival rate of synchronized and non-synchronized cultures as a function of exposure dose shows an exponential decay shape. No difference in viability of the cells occurred between synchronized and non-synchronized cultures. The pre-irradiation of cells with 100 and 200 Gy were most efficient to induce an adaptive response for the yeast cells. In this stage of work we proved the occurrence of the adaptive response in the case of synchronized yeast cultures exposed to gamma radiation. The results will be used in the future to investigate the dependence of this response on the cell cycle and the possibility to induce such a response by a low level electromagnetic field. (authors)

Consolidated ethanol production from Jerusalem artichoke tubers at elevated temperature by Saccharomyces cerevisiae engineered with inulinase expression through cell surface display.

Science.gov (United States)

Khatun, M Mahfuza; Liu, Chen-Guang; Zhao, Xin-Qing; Yuan, Wen-Jie; Bai, Feng-Wu

2017-02-01

Ethanol fermentation from Jerusalem artichoke tubers was performed at elevated temperatures by the consolidated bioprocessing strategy using Saccharomyces cerevisiae MK01 expressing inulinase through cell surface display. No significant difference was observed in yeast growth when temperature was controlled at 38 and 40 °C, respectively, but inulinase activity with yeast cells was substantially enhanced at 40 °C. As a result, enzymatic hydrolysis of inulin was facilitated and ethanol production was improved with 89.3 g/L ethanol produced within 72 h from 198.2 g/L total inulin sugars consumed. Similar results were also observed in ethanol production from Jerusalem artichoke tubers with 85.2 g/L ethanol produced within 72 h from 185.7 g/L total sugars consumed. On the other hand, capital investment on cooling facilities and energy consumption for running the facilities would be saved, since regular cooling water instead of chill water could be used to cool down the fermentation system.

Distribution patterns of Saccharomyces species in cultural landscapes of Germany.

Science.gov (United States)

Brysch-Herzberg, Michael; Seidel, Martin

2017-08-01

The distribution patterns of the three Saccharomyces species, Saccharomyces paradoxus, S. uvarum and S. cerevisiae, were investigated by a culture-dependent approach in order to understand better how these species propagate in the cultural landscape of Germany. Saccharomyces paradoxus, the closest relative of S. cerevisiae, is shown to be a true woodland species. It was frequently found in the soil under conifers indicating that S. paradoxus is an autochthonous member of the microbial community in this habitat. Physiological characteristics of the species like the Crabtree effect and high tolerance against ethanol suggest that the species is adapted to regular supply with considerable amounts of sugars. Additionally, a high proportion of the S. paradoxus strains isolated in this study are shown to have the rare ability to ferment melezitose. For these reasons, it is hypothesized that S. paradoxus may be closely associated with the honeydew system in forests. Saccharomyces cerevisiae was rare in most habitats and only exceeded the frequency of S. paradoxus in habitats characterized by modern agricultural mass production of fruit. Both the landscape structure and the agricultural system heavily influence the frequencies of Saccharomyces species. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

'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.

Induction of mitotic recombination by UV and diepoxybutane and its enhancement by hydroxyurea in Saccharomyces cerevisae

International Nuclear Information System (INIS)

Zaborowska, D.; Swietlinska, Z.; Zuk, J.

1983-01-01

Mitotic inter- and intra-genic recombination was induced by UV-irradiation and treatment with diepoxybutane (DEB) in 2 heteroallelic diploid strains of Saccharomyces cerevisiae SBTD and D7. Induction of the events tested was strongly potentiated by plating of mutagen-treated cells on growth media containing 0.03 M hydroxyurea (HU). (orig.)

Introducing a new breed of wine yeast: interspecific hybridisation between a commercial Saccharomyces cerevisiae wine yeast and Saccharomyces mikatae.

Science.gov (United States)

Bellon, Jennifer R; Schmid, Frank; Capone, Dimitra L; Dunn, Barbara L; Chambers, Paul J

2013-01-01

Interspecific hybrids are commonplace in agriculture and horticulture; bread wheat and grapefruit are but two examples. The benefits derived from interspecific hybridisation include the potential of generating advantageous transgressive phenotypes. This paper describes the generation of a new breed of wine yeast by interspecific hybridisation between a commercial Saccharomyces cerevisiae wine yeast strain and Saccharomyces mikatae, a species hitherto not associated with industrial fermentation environs. While commercially available wine yeast strains provide consistent and reliable fermentations, wines produced using single inocula are thought to lack the sensory complexity and rounded palate structure obtained from spontaneous fermentations. In contrast, interspecific yeast hybrids have the potential to deliver increased complexity to wine sensory properties and alternative wine styles through the formation of novel, and wider ranging, yeast volatile fermentation metabolite profiles, whilst maintaining the robustness of the wine yeast parent. Screening of newly generated hybrids from a cross between a S. cerevisiae wine yeast and S. mikatae (closely-related but ecologically distant members of the Saccharomyces sensu stricto clade), has identified progeny with robust fermentation properties and winemaking potential. Chemical analysis showed that, relative to the S. cerevisiae wine yeast parent, hybrids produced wines with different concentrations of volatile metabolites that are known to contribute to wine flavour and aroma, including flavour compounds associated with non-Saccharomyces species. The new S. cerevisiae x S. mikatae hybrids have the potential to produce complex wines akin to products of spontaneous fermentation while giving winemakers the safeguard of an inoculated ferment.

Lack of cortical endoplasmic reticulum protein Ist2 alters sodium accumulation in Saccharomyces cerevisiae cells

Czech Academy of Sciences Publication Activity Database

Papoušková, Klára; Andršová, Markéta; Sychrová, Hana

2017-01-01

Roč. 17, č. 2 (2017), č. článku fox011. ISSN 1567-1356 R&D Projects: GA MŠk(CZ) LH14297 Institutional support: RVO:67985823 Keywords : Saccharomyces cerevisiae * Ist2 * alkali-metal- cation homeostasis * sodium tolerance * sodium uptake * alkali-metal- cation transporters Subject RIV: EE - Microbiology, Virology OBOR OECD: Mycology Impact factor: 3.299, year: 2016

Investigation of the effect of water exposed to nonequilibrium contact plasma onto saccharomyces cerevisiae yeast

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S. Mykolenko

2015-05-01

Full Text Available Introduction. Additional treatment of water by nonequilibrium contact plasma allows improving consumer characteristics of bakery goods considerably. Determination of the effect of plasma-chemically activated water on morphological, cultural and physiological properties of Saccharomyces cerevisiae yeast is important from the technological point of view. Materials and Methods. Experimental investigations were carried out in the conditions of bacteriological laboratory by seeding the culture of yeasts of ТМ “Lvivski” and “Kryvorizki” on Sabouraud dense liquid nutrient media. The quantity of viable cells of microorganisms was determined by the method of Gould sector seeds. Morphology of the yeast was investigated by phase-contrast microscopy. Biotechnological properties of yeasts were determined on Giss media. Results. The paper establishes the effect of water exposed to nonequilibrium contact plasma on the sensitivity of Saccharomyces cerevisiae and shows absence of suppressive action of treated water with regard to cultural properties of microorganisms. The experiments prove that with the use of plasma-chemically activated water morphological characteristics and biochemical properties of bakery yeasts produced by Lviv and Kryvyi Rig yeast plants are preserved. Culturing of Saccharomyces cerevisiae yeast on the nutrient media prepared with the use of water exposed to nonequilibrium contact plasm resulted in 6,5–15 times’ increase in quantity of viable microorganisms compared with the control on the mains drinking water. Conclusions. Physiological properties of Saccharomyces cerevisiae yeast improved owing to use water exposed to nonequilibrium contact plasma. Results of investigations are recommended for using in yeast production and bread making.

Early manifestations of replicative aging in the yeast Saccharomyces cerevisiae

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Maksim I. Sorokin

2014-01-01

Full Text Available The yeast Saccharomyces cerevisiae is successfully used as a model organism to find genes responsible for lifespan control of higher organisms. As functional decline of higher eukaryotes can start as early as one quarter of the average lifespan, we asked whether S. cerevisiae can be used to model this manifestation of aging. While the average replicative lifespan of S. cerevisiae mother cells ranges between 15 and 30 division cycles, we found that resistances to certain stresses start to decrease much earlier. Looking into the mechanism, we found that knockouts of genes responsible for mitochondriato-nucleus (retrograde signaling, RTG1 or RTG3, significantly decrease the resistance of cells that generated more than four daughters, but not of the younger ones. We also found that even young mother cells frequently contain mitochondria with heterogeneous transmembrane potential and that the percentage of such cells correlates with replicative age. Together, these facts suggest that retrograde signaling starts to malfunction in relatively young cells, leading to accumulation of heterogeneous mitochondria within one cell. The latter may further contribute to a decline in stress resistances.

Aspergillus oryzae–Saccharomyces cerevisiae Consortium Allows Bio-Hybrid Fuel Cell to Run on Complex Carbohydrates

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Jahnke, Justin P.; Hoyt, Thomas; LeFors, Hannah M.; Sumner, James J.; Mackie, David M.

2016-01-01

Consortia of Aspergillus oryzae and Saccharomyces cerevisiae are examined for their abilities to turn complex carbohydrates into ethanol. To understand the interactions between microorganisms in consortia, Fourier-transform infrared spectroscopy is used to follow the concentrations of various metabolites such as sugars (e.g., glucose, maltose), longer chain carbohydrates, and ethanol to optimize consortia conditions for the production of ethanol. It is shown that with proper design A. oryzae can digest food waste simulants into soluble sugars that S. cerevisiae can ferment into ethanol. Depending on the substrate and conditions used, concentrations of 13% ethanol were achieved in 10 days. It is further shown that a direct alcohol fuel cell (FC) can be coupled with these A. oryzae-enabled S. cerevisiae fermentations using a reverse osmosis membrane. This “bio-hybrid FC” continually extracted ethanol from an ongoing consortium, enhancing ethanol production and allowing the bio-hybrid FC to run for at least one week. Obtained bio-hybrid FC currents were comparable to those from pure ethanol—water mixtures, using the same FC. The A. oryzae–S. cerevisiae consortium, coupled to a bio-hybrid FC, converted food waste simulants into electricity without any pre- or post-processing. PMID:27681904

Evidence for Divergent Evolution of Growth Temperature Preference in Sympatric Saccharomyces Species

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Gonçalves, Paula; Valério, Elisabete; Correia, Cláudia; de Almeida, João M. G. C. F.; Sampaio, José Paulo

2011-01-01

The genus Saccharomyces currently includes eight species in addition to the model yeast Saccharomyces cerevisiae, most of which can be consistently isolated from tree bark and soil. We recently found sympatric pairs of Saccharomyces species, composed of one cryotolerant and one thermotolerant species in oak bark samples of various geographic origins. In order to contribute to explain the occurrence in sympatry of Saccharomyces species, we screened Saccharomyces genomic data for protein divergence that might be correlated to distinct growth temperature preferences of the species, using the dN/dS ratio as a measure of protein evolution rates and pair-wise species comparisons. In addition to proteins previously implicated in growth at suboptimal temperatures, we found that glycolytic enzymes were among the proteins exhibiting higher than expected divergence when one cryotolerant and one thermotolerant species are compared. By measuring glycolytic fluxes and glycolytic enzymatic activities in different species and at different temperatures, we subsequently show that the unusual divergence of glycolytic genes may be related to divergent evolution of the glycolytic pathway aligning its performance to the growth temperature profiles of the different species. In general, our results support the view that growth temperature preference is a trait that may have undergone divergent selection in the course of ecological speciation in Saccharomyces. PMID:21674061

Spiritual pain and suffering.

Science.gov (United States)

Brunjes, George B

2010-01-01

Spiritual pain/suffering is commonly experienced by persons with life-limiting illness and their families. Physical pain itself can be exacerbated by non-physical causes such as fear, anxiety, grief, unresolved guilt, depression and unmet spiritual meets. Likewise, the inability to manage physical pain well can be due to emotional and spiritual needs. This is why a holistic, interdisciplinary assessment of pain and suffering is required for each patient and family. The mind, body and spirit are understood in relationship to each other and, in those cases, in relationship to a deity or deities are important to understand. Cultural interpretations of pain and suffering may conflict with the goals of palliative care. Understanding the spiritual framework of the patient and family can help to assure that the physical and spiritual suffering of the patient can be eliminated to provide a peaceful death. Spiritual practices may help in the management of physical pain.

Heterologous expression of MlcE in Saccharomyces cerevisiae provides resistance to natural and semi-synthetic statins

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Ana Ley

2015-12-01

Full Text Available Statins are inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase, the key enzyme in cholesterol biosynthesis. Their extensive use in treatment and prevention of cardiovascular diseases placed statins among the best selling drugs. Construction of Saccharomyces cerevisiae cell factory for the production of high concentrations of natural statins will require establishment of a non-destructive self-resistance mechanism to overcome the undesirable growth inhibition effects of statins. To establish active export of statins from yeast, and thereby detoxification, we integrated a putative efflux pump-encoding gene mlcE from the mevastatin-producing Penicillium citrinum into the S. cerevisiae genome. The resulting strain showed increased resistance to both natural statins (mevastatin and lovastatin and semi-synthetic statin (simvastatin when compared to the wild type strain. Expression of RFP-tagged mlcE showed that MlcE is localized to the yeast plasma and vacuolar membranes. We provide a possible engineering strategy for improvement of future yeast based production of natural and semi-synthetic statins. Keywords: Polyketide, Statins, Saccharomyces cerevisiae, Transport, Cell factory, Resistance

Comparative study of bio-ethanol production from mahula (Madhuca latifolia L.) flowers by Saccharomyces cerevisiae cells immobilized in agar agar and Ca-alginate matrices

Energy Technology Data Exchange (ETDEWEB)

Behera, Shuvashish; Mohanty, Rama Chandra [Department of Botany, Utkal University, Vani Vihar, Bhubaneswar 751004, Orissa (India); Kar, Shaktimay; Ray, Ramesh Chandra [Microbiology Laboratory, Central Tuber Crops Research Institute (Regional Centre), Bhubaneswar 751019, Orissa (India)

2010-01-15

Batch fermentation of mahula (Madhuca latifolia L., a tree commonly found in tropical rain forest) flowers was carried out using immobilized cells (in agar agar and calcium alginate) and free cells of Saccharomyces cerevisiae. The ethanol yields were 151.2, 154.5 and 149.1 g kg{sup -1} flowers using immobilized (in agar agar and calcium alginate) and free cells, respectively. Cell entrapment in calcium alginate was found to be marginally superior to those in agar agar (2.2% more) as well as over free cell (3.5% more) as regard to ethanol yield from mahula flowers is concerned. Further, the immobilized cells were physiologically active at least for three cycles [150.6, 148.5 and 146.5 g kg{sup -1} (agar agar) and 152.8, 151.5 and 149.5 g kg{sup -1} flowers (calcium alginate) for first, second and third cycle, respectively] of ethanol fermentation without apparently lowering the productivity. Mahula flowers, a renewable, non-food-grade cheap carbohydrate substrate from non-agricultural environment such as forest can serve as an alternative to food grade sugar/starchy crops such as maize, sugarcane for bio-ethanol production. (author)

Copper Tolerance and Biosorption of Saccharomyces cerevisiae during Alcoholic Fermentation

Science.gov (United States)

Liu, Ling-ling; Jia, Bo; Zhao, Fang; Huang, Wei-dong; Zhan, Ji-cheng

2015-01-01

At high levels, copper in grape mash can inhibit yeast activity and cause stuck fermentations. Wine yeast has limited tolerance of copper and can reduce copper levels in wine during fermentation. This study aimed to understand copper tolerance of wine yeast and establish the mechanism by which yeast decreases copper in the must during fermentation. Three strains of Saccharomyces cerevisiae (lab selected strain BH8 and industrial strains AWRI R2 and Freddo) and a simple model fermentation system containing 0 to 1.50 mM Cu2+ were used. ICP-AES determined Cu ion concentration in the must decreasing differently by strains and initial copper levels during fermentation. Fermentation performance was heavily inhibited under copper stress, paralleled a decrease in viable cell numbers. Strain BH8 showed higher copper-tolerance than strain AWRI R2 and higher adsorption than Freddo. Yeast cell surface depression and intracellular structure deformation after copper treatment were observed by scanning electron microscopy and transmission electron microscopy; electronic differential system detected higher surface Cu and no intracellular Cu on 1.50 mM copper treated yeast cells. It is most probably that surface adsorption dominated the biosorption process of Cu2+ for strain BH8, with saturation being accomplished in 24 h. This study demonstrated that Saccharomyces cerevisiae strain BH8 has good tolerance and adsorption of Cu, and reduces Cu2+ concentrations during fermentation in simple model system mainly through surface adsorption. The results indicate that the strain selected from China’s stress-tolerant wine grape is copper tolerant and can reduce copper in must when fermenting in a copper rich simple model system, and provided information for studies on mechanisms of heavy metal stress. PMID:26030864

Copper Tolerance and Biosorption of Saccharomyces cerevisiae during Alcoholic Fermentation.

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Xiang-Yu Sun

Full Text Available At high levels, copper in grape mash can inhibit yeast activity and cause stuck fermentations. Wine yeast has limited tolerance of copper and can reduce copper levels in wine during fermentation. This study aimed to understand copper tolerance of wine yeast and establish the mechanism by which yeast decreases copper in the must during fermentation. Three strains of Saccharomyces cerevisiae (lab selected strain BH8 and industrial strains AWRI R2 and Freddo and a simple model fermentation system containing 0 to 1.50 mM Cu2+ were used. ICP-AES determined Cu ion concentration in the must decreasing differently by strains and initial copper levels during fermentation. Fermentation performance was heavily inhibited under copper stress, paralleled a decrease in viable cell numbers. Strain BH8 showed higher copper-tolerance than strain AWRI R2 and higher adsorption than Freddo. Yeast cell surface depression and intracellular structure deformation after copper treatment were observed by scanning electron microscopy and transmission electron microscopy; electronic differential system detected higher surface Cu and no intracellular Cu on 1.50 mM copper treated yeast cells. It is most probably that surface adsorption dominated the biosorption process of Cu2+ for strain BH8, with saturation being accomplished in 24 h. This study demonstrated that Saccharomyces cerevisiae strain BH8 has good tolerance and adsorption of Cu, and reduces Cu2+ concentrations during fermentation in simple model system mainly through surface adsorption. The results indicate that the strain selected from China's stress-tolerant wine grape is copper tolerant and can reduce copper in must when fermenting in a copper rich simple model system, and provided information for studies on mechanisms of heavy metal stress.

Construction of killer industrial yeast Saccharomyces cerevisiae HAU-1 and its fermentation performance

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Bijender K. Bajaj

2010-06-01

Full Text Available Saccharomyces cerevisiae HAU-1, a time tested industrial yeast possesses most of the desirable fermentation characteristics like fast growth and fermentation rate, osmotolerance, high ethanol tolerance, ability to ferment molasses, and to ferment at elevated temperatures etc. However, this yeast was found to be sensitive against the killer strains of Saccharomyces cerevisiae. In the present study, killer trait was introduced into Saccharomyces cerevisiae HAU-1 by protoplast fusion with Saccharomyces cerevisiae MTCC 475, a killer strain. The resultant fusants were characterized for desirable fermentation characteristics. All the technologically important characteristics of distillery yeast Saccharomyces cerevisiae HAU-1 were retained in the fusants, and in addition the killer trait was also introduced into them. Further, the killer activity was found to be stably maintained during hostile conditions of ethanol fermentations in dextrose or molasses, and even during biomass recycling.

Improvement of ethanol-tolerance of haploid Saccharomyces diastaticus

International Nuclear Information System (INIS)

Song, S.H.; Kim, K.; Lee, M.W.

1994-01-01

Several mutation procedures have been compared to obtain an ethanol-tolerant Saccharomyces diastaticus strain secreting glucoamylase. These procedures include spontaneous mutation, EMS treatment, UV irradiation, and combination of EMS treatment and UV irradiation. All these methods were followed by adaptation of the yeast cells to gradually higher ethanol concentration. Among these procedures, the combined method of EMS treatment and UV irradiation gave the promising result, i.e. the ethanol tolerance of the yeast increased from 11.5%(v/v) to 14.0%(v/v). Respiratory deficient petite mutants of industrial and ethanol-tolerant yeast strains have been isolated and hybridized with haploid S. diastaticus strains. The resulting hybrids showed increased ethanol tolerance and starch-fermentability

Thermal resistance of Saccharomyces yeast ascospores in beers.

Science.gov (United States)

Milani, Elham A; Gardner, Richard C; Silva, Filipa V M

2015-08-03

The industrial production of beer ends with a process of thermal pasteurization. Saccharomyces cerevisiae and Saccharomyces pastorianus are yeasts used to produce top and bottom fermenting beers, respectively. In this research, first the sporulation rate of 12 Saccharomyces strains was studied. Then, the thermal resistance of ascospores of three S. cerevisiae strains (DSMZ 1848, DSMZ 70487, Ethanol Red(®)) and one strain of S. pastorianus (ATCC 9080) was determined in 4% (v/v) ethanol lager beer. D60 °C-values of 11.2, 7.5, 4.6, and 6.0 min and z-values of 11.7, 14.3, 12.4, and 12.7 °C were determined for DSMZ 1848, DSMZ 70487, ATCC 9080, and Ethanol Red(®), respectively. Lastly, experiments with 0 and 7% (v/v) beers were carried out to investigate the effect of ethanol content on the thermal resistance of S. cerevisiae (DSMZ 1848). D55 °C-values of 34.2 and 15.3 min were obtained for 0 and 7% beers, respectively, indicating lower thermal resistance in the more alcoholic beer. These results demonstrate similar spore thermal resistance for different Saccharomyces strains and will assist in the design of appropriate thermal pasteurization conditions for preserving beers with different alcohol contents. Copyright © 2015 Elsevier B.V. All rights reserved.

Industrial systems biology of Saccharomyces cerevisiae enables novel succinic acid cell factory.

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José Manuel Otero

Full Text Available Saccharomyces cerevisiae is the most well characterized eukaryote, the preferred microbial cell factory for the largest industrial biotechnology product (bioethanol, and a robust commerically compatible scaffold to be exploitted for diverse chemical production. Succinic acid is a highly sought after added-value chemical for which there is no native pre-disposition for production and accmulation in S. cerevisiae. The genome-scale metabolic network reconstruction of S. cerevisiae enabled in silico gene deletion predictions using an evolutionary programming method to couple biomass and succinate production. Glycine and serine, both essential amino acids required for biomass formation, are formed from both glycolytic and TCA cycle intermediates. Succinate formation results from the isocitrate lyase catalyzed conversion of isocitrate, and from the α-keto-glutarate dehydrogenase catalyzed conversion of α-keto-glutarate. Succinate is subsequently depleted by the succinate dehydrogenase complex. The metabolic engineering strategy identified included deletion of the primary succinate consuming reaction, Sdh3p, and interruption of glycolysis derived serine by deletion of 3-phosphoglycerate dehydrogenase, Ser3p/Ser33p. Pursuing these targets, a multi-gene deletion strain was constructed, and directed evolution with selection used to identify a succinate producing mutant. Physiological characterization coupled with integrated data analysis of transcriptome data in the metabolically engineered strain were used to identify 2(nd-round metabolic engineering targets. The resulting strain represents a 30-fold improvement in succinate titer, and a 43-fold improvement in succinate yield on biomass, with only a 2.8-fold decrease in the specific growth rate compared to the reference strain. Intuitive genetic targets for either over-expression or interruption of succinate producing or consuming pathways, respectively, do not lead to increased succinate. Rather, we

The SFP1 gene product of Saccharomyces cerevisiae regulates G2/M transitions during the mitotic cell cycle and DNA-damage response

International Nuclear Information System (INIS)

Xu, Z.; Norris, D.

1998-01-01

In eukaryotic cells, checkpoint pathways arrest cell-cycle progression if a particular event has failed to complete appropriately or if an important intracellular structure is defective or damaged. Saccharomyces cerevisiae strains that lack the SFP1 gene fail to arrest at the G2 DNA-damage checkpoint in response to genomic injury, but maintain their ability to arrest at the replication and spindle-assembly checkpoints. sfp1D mutants are characterized by a premature entrance into mitosis during a normal (undamaged) cell cycle, while strains that overexpress Sfp1p exhibit delays in G2. Sfp1p therefore acts as a repressor of the G2/M transition, both in the normal cell cycle and in the G2 checkpoint pathway. Sfp1 is a nuclear protein with two Cys2His2 zinc-finger domains commonly found in transcription factors. We propose that Sfp1p regulates the expression of gene products involved in the G2/M transition during the mitotic cell cycle and the DNA-damage response. In support of this model, overexpression of Sfp1p induces the expression of the PDS1 gene, which is known to encode a protein that regulates the G2 checkpoint. (author)

Fungal genomics beyond Saccharomyces cerevisiae?

DEFF Research Database (Denmark)

Hofmann, Gerald; Mcintyre, Mhairi; Nielsen, Jens

2003-01-01

Fungi are used extensively in both fundamental research and industrial applications. Saccharomyces cerevisiae has been the model organism for fungal research for many years, particularly in functional genomics. However, considering the diversity within the fungal kingdom, it is obvious...

Metabolic engineering of Saccharomyces cerevisiae for overproduction of triacylglycerols

DEFF Research Database (Denmark)

Ferreira, Raphael; Teixeira, Paulo Goncalves; Gossing, Michael

2018-01-01

Triacylglycerols (TAGs) are valuable versatile compounds that can be used as metabolites for nutrition and health, as well as feedstocks for biofuel production. Although Saccharomyces cerevisiae is the favored microbial cell factory for industrial production of biochemicals, it does not produce...... large amounts of lipids and TAGs comprise only ~1% of its cell dry weight. Here, we engineered S. cerevisiae to reorient its metabolism for overproduction of TAGs, by regulating lipid droplet associated-proteins involved in TAG synthesis and hydrolysis. We implemented a push-and-pull strategy...... PXA1 led to accumulation of  254 mg∙gCDW−1. The TAG levels achieved here are the highest titer reported in S. cerevisiae, reaching 27.4% of the maximum theoretical yield in minimal medium with 2% glucose. This work shows the potential of using an industrially established and robust yeast species...

Introducing a new breed of wine yeast: interspecific hybridisation between a commercial Saccharomyces cerevisiae wine yeast and Saccharomyces mikatae.

Directory of Open Access Journals (Sweden)

Jennifer R Bellon

Full Text Available Interspecific hybrids are commonplace in agriculture and horticulture; bread wheat and grapefruit are but two examples. The benefits derived from interspecific hybridisation include the potential of generating advantageous transgressive phenotypes. This paper describes the generation of a new breed of wine yeast by interspecific hybridisation between a commercial Saccharomyces cerevisiae wine yeast strain and Saccharomyces mikatae, a species hitherto not associated with industrial fermentation environs. While commercially available wine yeast strains provide consistent and reliable fermentations, wines produced using single inocula are thought to lack the sensory complexity and rounded palate structure obtained from spontaneous fermentations. In contrast, interspecific yeast hybrids have the potential to deliver increased complexity to wine sensory properties and alternative wine styles through the formation of novel, and wider ranging, yeast volatile fermentation metabolite profiles, whilst maintaining the robustness of the wine yeast parent. Screening of newly generated hybrids from a cross between a S. cerevisiae wine yeast and S. mikatae (closely-related but ecologically distant members of the Saccharomyces sensu stricto clade, has identified progeny with robust fermentation properties and winemaking potential. Chemical analysis showed that, relative to the S. cerevisiae wine yeast parent, hybrids produced wines with different concentrations of volatile metabolites that are known to contribute to wine flavour and aroma, including flavour compounds associated with non-Saccharomyces species. The new S. cerevisiae x S. mikatae hybrids have the potential to produce complex wines akin to products of spontaneous fermentation while giving winemakers the safeguard of an inoculated ferment.

Introducing a New Breed of Wine Yeast: Interspecific Hybridisation between a Commercial Saccharomyces cerevisiae Wine Yeast and Saccharomyces mikatae

Science.gov (United States)

Bellon, Jennifer R.; Schmid, Frank; Capone, Dimitra L.; Dunn, Barbara L.; Chambers, Paul J.

2013-01-01

Interspecific hybrids are commonplace in agriculture and horticulture; bread wheat and grapefruit are but two examples. The benefits derived from interspecific hybridisation include the potential of generating advantageous transgressive phenotypes. This paper describes the generation of a new breed of wine yeast by interspecific hybridisation between a commercial Saccharomyces cerevisiae wine yeast strain and Saccharomyces mikatae, a species hitherto not associated with industrial fermentation environs. While commercially available wine yeast strains provide consistent and reliable fermentations, wines produced using single inocula are thought to lack the sensory complexity and rounded palate structure obtained from spontaneous fermentations. In contrast, interspecific yeast hybrids have the potential to deliver increased complexity to wine sensory properties and alternative wine styles through the formation of novel, and wider ranging, yeast volatile fermentation metabolite profiles, whilst maintaining the robustness of the wine yeast parent. Screening of newly generated hybrids from a cross between a S. cerevisiae wine yeast and S. mikatae (closely-related but ecologically distant members of the Saccharomyces sensu stricto clade), has identified progeny with robust fermentation properties and winemaking potential. Chemical analysis showed that, relative to the S. cerevisiae wine yeast parent, hybrids produced wines with different concentrations of volatile metabolites that are known to contribute to wine flavour and aroma, including flavour compounds associated with non-Saccharomyces species. The new S. cerevisiae x S. mikatae hybrids have the potential to produce complex wines akin to products of spontaneous fermentation while giving winemakers the safeguard of an inoculated ferment. PMID:23614011

Sucrose fermentation by Saccharomyces cerevisiae lacking hexose transport.

Science.gov (United States)

Batista, Anderson S; Miletti, Luiz C; Stambuk, Boris U

2004-01-01

Sucrose is the major carbon source used by Saccharomyces cerevisiae during production of baker's yeast, fuel ethanol and several distilled beverages. It is generally accepted that sucrose fermentation proceeds through extracellular hydrolysis of the sugar, mediated by the periplasmic invertase, producing glucose and fructose that are transported into the cells and metabolized. In the present work we analyzed the contribution to sucrose fermentation of a poorly characterized pathway of sucrose utilization by S. cerevisiae cells, the active transport of the sugar through the plasma membrane and its intracellular hydrolysis. A yeast strain that lacks the major hexose transporters (hxt1-hxt7 and gal2) is incapable of growing on or fermenting glucose or fructose. Our results show that this hxt-null strain is still able to ferment sucrose due to direct uptake of the sugar into the cells. Deletion of the AGT1 gene, which encodes a high-affinity sucrose-H(+) symporter, rendered cells incapable of sucrose fermentation. Since sucrose is not an inducer of the permease, expression of the AGT1 must be constitutive in order to allow growth of the hxt-null strain on sucrose. The molecular characterization of active sucrose transport and fermentation by S. cerevisiae cells opens new opportunities to optimize yeasts for sugarcane-based industrial processes.

Response of Saccharomyces cerevisiae to D-limonene-induced oxidative stress.

Science.gov (United States)

Liu, Jidong; Zhu, Yibo; Du, Guocheng; Zhou, Jingwen; Chen, Jian

2013-07-01

In the present study, we investigated the mode of cell response induced by D-limonene in Saccharomyces cerevisiae. D-limonene treatment was found to be accompanied by intracellular accumulation of reactive oxygen species (ROS). Since ROS impair cell membranes, an engineered strain with enhanced membrane biosynthesis exhibited a higher tolerance to D-limonene. Subsequent addition of an ROS scavenger significantly reduced the ROS level and alleviated cell growth inhibition. Thus, D-limonene-induced ROS accumulation plays an important role in cell death in S. cerevisiae. In D-limonene-treated S. cerevisiae strains, higher levels of antioxidants, antioxidant enzymes, and nicotinamide adenine dinucleotide phosphate (NADPH) were synthesized. Quantitative real-time PCR results also verified that D-limonene treatment triggered upregulation of genes involved in the antioxidant system and the regeneration of NADPH at the transcription level in S. cerevisiae. These data indicate that D-limonene treatment results in intracellular ROS accumulation, an important factor in cell death, and several antioxidant mechanisms in S. cerevisiae were enhanced in response to D-limonene treatment.

Anaerobic organic acid metabolism of Candida zemplinina in comparison with Saccharomyces wine yeasts.

Science.gov (United States)

Magyar, Ildikó; Nyitrai-Sárdy, Diána; Leskó, Annamária; Pomázi, Andrea; Kállay, Miklós

2014-05-16

Organic acid production under oxygen-limited conditions has been thoroughly studied in the Saccharomyces species, but practically never investigated in Candida zemplinina, which seems to be an acidogenic species under oxidative laboratory conditions. In this study, several strains of C. zemplinina were tested for organic acid metabolism, in comparison with Saccharomyces cerevisiae, Saccharomyces uvarum and Candida stellata, under fermentative conditions. Only C. stellata produced significantly higher acidity in simple minimal media (SM) with low sugar content and two different nitrogen sources (ammonia or glutamic acid) at low level. However, the acid profile differed largely between the Saccharomyces and Candida species and showed inverse types of N-dependence in some cases. Succinic acid production was strongly enhanced on glutamic acid in Saccharomyces species, but not in Candida species. 2-oxoglutarate production was strongly supported on ammonium nitrogen in Candida species, but remained low in Saccharomyces. Candida species, C. stellata in particular, produced more pyruvic acid regardless of N-sources. From the results, we concluded that the anaerobic organic acid metabolisms of C. zemplinina and C. stellata are different from each other and also from that of the Saccharomyces species. In the formation of succinic acid, the oxidative pathway from glutamic acid seems to play little or no role in C. zemplinina. The reductive branch of the TCA cycle, however, produces acidic intermediates (malic, fumaric, and succinic acid) in a level comparable with the production of the Saccharomyces species. An unidentified organic acid, which was produced on glutamic acid only by the Candida species, needs further investigation. Copyright © 2014 Elsevier B.V. All rights reserved.

The Hsp70 homolog Ssb and the 14-3-3 protein Bmh1 jointly regulate transcription of glucose repressed genes in Saccharomyces cerevisiae.

Science.gov (United States)

Hübscher, Volker; Mudholkar, Kaivalya; Chiabudini, Marco; Fitzke, Edith; Wölfle, Tina; Pfeifer, Dietmar; Drepper, Friedel; Warscheid, Bettina; Rospert, Sabine

2016-07-08

Chaperones of the Hsp70 family interact with a multitude of newly synthesized polypeptides and prevent their aggregation. Saccharomyces cerevisiae cells lacking the Hsp70 homolog Ssb suffer from pleiotropic defects, among others a defect in glucose-repression. The highly conserved heterotrimeric kinase SNF1/AMPK (AMP-activated protein kinase) is required for the release from glucose-repression in yeast and is a key regulator of energy balance also in mammalian cells. When glucose is available the phosphatase Glc7 keeps SNF1 in its inactive, dephosphorylated state. Dephosphorylation depends on Reg1, which mediates targeting of Glc7 to its substrate SNF1. Here we show that the defect in glucose-repression in the absence of Ssb is due to the ability of the chaperone to bridge between the SNF1 and Glc7 complexes. Ssb performs this post-translational function in concert with the 14-3-3 protein Bmh, to which Ssb binds via its very C-terminus. Raising the intracellular concentration of Ssb or Bmh enabled Glc7 to dephosphorylate SNF1 even in the absence of Reg1. By that Ssb and Bmh efficiently suppressed transcriptional deregulation of Δreg1 cells. The findings reveal that Ssb and Bmh comprise a new chaperone module, which is involved in the fine tuning of a phosphorylation-dependent switch between respiration and fermentation. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

Saccharomyces cerevisiae UE-ME3 is a good strain for isoproturon biorremediation?

OpenAIRE

Candeias, M; Alves-Pereira, I; Ferreira, R

2010-01-01

Isoproturon, an herbicide of pre- and pos-emergence of Autumn-Winter crops, persists occasionally in soil, groundwater and biological systems at levels above those established by European Directives. Saccharomyces cerevisiae UE-ME3 exposed in stationary phase to 50 and 100 mM isoproturon exhibit growth rates higher than control or exposed cells to 5 and 25 mM of this phenylurea. However, in S.cerevisiae UE-ME3 grown in the presence of 5 mM isoproturon, were observed a decrease of ...

Modifying factors of the cellular concentration of photolyase molecules in Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Fukui, A.; Laskowski, W.

1984-01-01

The effects of preillumination with photoreactivating light flashes before UV-irradiation on the number of photoreactivable complexes consisting of UV-induced DNA-damages and active photolyase molecules (Nsub(PREact), on the fluence decrements ΔDsub(PRE), that are obtained from two UV-survival curves without and with 1 flash photoreactivation and proportional to Nsub(PREact) were determined in haploid Saccharomyces cerevisiae cells. ΔDsub(PRE) increased by preillumination from 0.115 J m -2 to 0.460 Jm -2 and from 0.376 Jm -2 to 0.494 Jm -2 in cells in logarithmic growth phase and in stationary growth phase, respectively. ΔDsub(PRE) in log-cells that were preilluminated before and after resuspension in buffer at 40 0 C for 60 min was larger than ΔDsub(PRE) in log-cells preilluminated only after resuspension in buffer. (author)

Phosphorylation of protein synthesis initiation factor 2 (elF-2) in the yeast Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Romero, D.P.

1986-01-01

Initiation Factor 2 (elF-2) in the yeast Saccharomyces cerevisiae is comprised of 3 subunits. The control of protein synthesis in mammalian cells have been shown to involve the phosphorylation of the small (alpha) subunit by a specific protein kinase. Phosphorylation results in an inhibition of protein synthesis. In order to determine whether or not an analogous system is operative in yeast, the phosphorylation state of the alpha subunit of elF-2 in Saccharomyces was determined during various growth and nongrowth conditions. Cells were radiolabelled with 32 P and 35 S, and the whole cell lysates were analyzed by two dimensional gel electrophoresis. These experiments revealed that the smallest subunit (alpha, M/sub r/ = 31,000) is a phosphoprotein in vivo under a variety of growth and nongrowth conditions. This is in direct contrast to the pattern exhibited in mammalian cells. The fact that the small subunit of elF-2 in yeast is phosphorylated under a variety of physiological conditions indicates that such a covalent modification is important for some aspects of elF-2 function. In order to investigate this problem further, a protein kinase that specifically labels the alpha subunit of elF-2 in vitro was isolated. The kinase is not autophosphorylating, utilizes ATP as a phosphate donor, phosphorylates an exogenous protein, casein, modifies serine residues in elF-2, is cyclic nucleotide-independent, and is strongly inhibited by heparin

Cell mass and cell cycle dynamics of an asynchronous budding yeast population

DEFF Research Database (Denmark)

Lencastre Fernandes, Rita; Carlquist, Magnus; Lundin, Luisa

2013-01-01

of model predictions for cell property distributions against experimental data is scarce. This study focuses on the experimental and mathematical description of the dynamics of cell size and cell cycle position distributions, of a population of Saccharomyces cerevisiae, in response to the substrate...

Effect of pulsed electric fields (PEF) on accumulation of selenium and zinc ions in Saccharomyces cerevisiae cells.

Science.gov (United States)

Pankiewicz, Urszula; Sujka, Monika; Kowalski, Radosław; Mazurek, Artur; Włodarczyk-Stasiak, Marzena; Jamroz, Jerzy

2017-04-15

The cultures of Saccharomyces cerevisiae were treated with pulsed electric fields (PEF) in order to obtain a maximum accumulation of selenium and zinc ions (simultaneously) in the biomass. The following concentrations: 100μgSe/ml and 150μgZn/ml medium were assumed to be optimal for the maximum accumulation of these ions, that is 43.07mg/gd.m. for selenium and 14.48mg/gd.m. for zinc, in the cultures treated with PEF. At optimal PEF parameters: electric field strength of 3kV/cm and pulse width of 10μs after the treatment of 20-h culture for 10min, the maximum accumulation of both ions in the yeast cells was observed. Application of PEF caused the increase of ions accumulation by 65% for selenium and 100% for zinc. Optimization of PEF parameters led to the further rise in the both ions accumulation resulting in over 2-fold and 2.5-fold higher concentration of selenium and zinc. Copyright © 2016 Elsevier Ltd. All rights reserved.

Cell Size Influences the Reproductive Potential and Total Lifespan of the Saccharomyces cerevisiae Yeast as Revealed by the Analysis of Polyploid Strains

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Renata Zadrag-Tecza

2018-01-01

Full Text Available The total lifespan of the yeast Saccharomyces cerevisiae may be divided into two phases: the reproductive phase, during which the cell undergoes mitosis cycles to produce successive buds, and the postreproductive phase, which extends from the last division to cell death. These phases may be regulated by a common mechanism or by distinct ones. In this paper, we proposed a more comprehensive approach to reveal the mechanisms that regulate both reproductive potential and total lifespan in cell size context. Our study was based on yeast cells, whose size was determined by increased genome copy number, ranging from haploid to tetraploid. Such experiments enabled us to test the hypertrophy hypothesis, which postulates that excessive size achieved by the cell—the hypertrophy state—is the reason preventing the cell from further proliferation. This hypothesis defines the reproductive potential value as the difference between the maximal size that a cell can reach and the threshold value, which allows a cell to undergo its first cell cycle and the rate of the cell size to increase per generation. Here, we showed that cell size has an important impact on not only the reproductive potential but also the total lifespan of this cell. Moreover, the maximal cell size value, which limits its reproduction capacity, can be regulated by different factors and differs depending on the strain ploidy. The achievement of excessive size by the cell (hypertrophic state may lead to two distinct phenomena: the cessation of reproduction without “mother” cell death and the cessation of reproduction with cell death by bursting, which has not been shown before.

Benefits of Suffering: Communicator Suffering. Benefiting, and Influence.

Science.gov (United States)

1980-07-01

Christian church developed, largely around this act of sacrifice. In the political realm, Hitler, Ghandi and Lenin all spent time in jail and/or exile...revolutionary leaders such as Mao or Ghandi have often used public displays of sacrifice or suffering to demonstrate their own dedication and gain

ATG18 and FAB1 are involved in dehydration stress tolerance in Saccharomyces cerevisiae.

Science.gov (United States)

López-Martínez, Gema; Margalef-Català, Mar; Salinas, Francisco; Liti, Gianni; Cordero-Otero, Ricardo

2015-01-01

Recently, different dehydration-based technologies have been evaluated for the purpose of cell and tissue preservation. Although some early results have been promising, they have not satisfied the requirements for large-scale applications. The long experience of using quantitative trait loci (QTLs) with the yeast Saccharomyces cerevisiae has proven to be a good model organism for studying the link between complex phenotypes and DNA variations. Here, we use QTL analysis as a tool for identifying the specific yeast traits involved in dehydration stress tolerance. Three hybrids obtained from stable haploids and sequenced in the Saccharomyces Genome Resequencing Project showed intermediate dehydration tolerance in most cases. The dehydration resistance trait of 96 segregants from each hybrid was quantified. A smooth, continuous distribution of the anhydrobiosis tolerance trait was found, suggesting that this trait is determined by multiple QTLs. Therefore, we carried out a QTL analysis to identify the determinants of this dehydration tolerance trait at the genomic level. Among the genes identified after reciprocal hemizygosity assays, RSM22, ATG18 and DBR1 had not been referenced in previous studies. We report new phenotypes for these genes using a previously validated test. Finally, our data illustrates the power of this approach in the investigation of the complex cell dehydration phenotype.

ATG18 and FAB1 are involved in dehydration stress tolerance in Saccharomyces cerevisiae.

Directory of Open Access Journals (Sweden)

Gema López-Martínez

Full Text Available Recently, different dehydration-based technologies have been evaluated for the purpose of cell and tissue preservation. Although some early results have been promising, they have not satisfied the requirements for large-scale applications. The long experience of using quantitative trait loci (QTLs with the yeast Saccharomyces cerevisiae has proven to be a good model organism for studying the link between complex phenotypes and DNA variations. Here, we use QTL analysis as a tool for identifying the specific yeast traits involved in dehydration stress tolerance. Three hybrids obtained from stable haploids and sequenced in the Saccharomyces Genome Resequencing Project showed intermediate dehydration tolerance in most cases. The dehydration resistance trait of 96 segregants from each hybrid was quantified. A smooth, continuous distribution of the anhydrobiosis tolerance trait was found, suggesting that this trait is determined by multiple QTLs. Therefore, we carried out a QTL analysis to identify the determinants of this dehydration tolerance trait at the genomic level. Among the genes identified after reciprocal hemizygosity assays, RSM22, ATG18 and DBR1 had not been referenced in previous studies. We report new phenotypes for these genes using a previously validated test. Finally, our data illustrates the power of this approach in the investigation of the complex cell dehydration phenotype.

The antagonistic effect of Saccharomyces boulardii on Candida albicans filamentation, adhesion and biofilm formation.

Science.gov (United States)

Krasowska, Anna; Murzyn, Anna; Dyjankiewicz, Agnieszka; Łukaszewicz, Marcin; Dziadkowiec, Dorota

2009-12-01

The dimorphic fungus Candida albicans is a member of the normal flora residing in the intestinal tract of humans. In spite of this, under certain conditions it can induce both superficial and serious systemic diseases, as well as be the cause of gastrointestinal infections. Saccharomyces boulardii is a yeast strain that has been shown to have applications in the prevention and treatment of intestinal infections caused by bacterial pathogens. The purpose of this study was to determine whether S. boulardii affects the virulence factors of C. albicans. We demonstrate the inhibitory effect of live S. boulardii cells on the filamentation (hyphae and pseudohyphae formation) of C. albicans SC5314 strain proportional to the amount of S. boulardii added. An extract from S. boulardii culture has a similar effect. Live S. boulardii and the extract from S. boulardii culture filtrate diminish C. albicans adhesion to and subsequent biofilm formation on polystyrene surfaces under both aerobic and microaerophilic conditions. This effect is very strong and requires lower doses of S. boulardii cells or concentrations of the extract than serum-induced filamentation tests. Saccharomyces boulardii has a strong negative effect on very important virulence factors of C. albicans, i.e. the ability to form filaments and to adhere and form biofilms on plastic surfaces.

Advances in metabolic engineering of yeast Saccharomyces cerevisiae for production of chemicals.

Science.gov (United States)

Borodina, Irina; Nielsen, Jens

2014-05-01

Yeast Saccharomyces cerevisiae is an important industrial host for production of enzymes, pharmaceutical and nutraceutical ingredients and recently also commodity chemicals and biofuels. Here, we review the advances in modeling and synthetic biology tools and how these tools can speed up the development of yeast cell factories. We also present an overview of metabolic engineering strategies for developing yeast strains for production of polymer monomers: lactic, succinic, and cis,cis-muconic acids. S. cerevisiae has already firmly established itself as a cell factory in industrial biotechnology and the advances in yeast strain engineering will stimulate development of novel yeast-based processes for chemicals production. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Evaluation of emulsifier stability of biosurfactant produced by Saccharomyces lipolytica CCT-0913

OpenAIRE

Lima,Álvaro Silva; Alegre,Ranulfo Monte

2009-01-01

Surface-active compounds of biological origin are widely used for many industries (cosmetic, food, petrochemical). The Saccharomyces lipolytica CCT-0913 was able to grow and produce a biosurfactant on 5% (v/v) diesel-oil at pH 5.0 and 32ºC. The cell-free broth emulsified and stabilized the oil-in-water emulsion through a first order kinetics. The results showed that the initial pH value and temperature influenced the emulsifier stability (ES), which was the time when oil was separated. The bi...

Regularities of ''rapid'' repair in radiosensitive mutants of diploid yeasts Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Glazunov, A.V.; Kapul'tsevich, Yu.G.

1982-01-01

A study was made of ''rapid'' repair in radiosensitive mutants of diploid yeast Saccharomyces cerevisiae after irradiation with ν-quanta and α-particles. It was shown that the capacity of ''rapid'' repair does not always correlate with the ability of ''slow'' postirradiation repair of viability of yeast cells. A conclusion is made that ''rapid'' and ''slow'' repair are independent processes. It was found that ''rapid'' repair of the studied strains of diploid yeast is more effective after exposure to ν-quanta than α-particles

Induction of homologous recombination in Saccharomyces cerevisiae.

Science.gov (United States)

Simon, J R; Moore, P D

1988-09-01

We have investigated the effects of UV irradiation of Saccharomyces cerevisiae in order to distinguish whether UV-induced recombination results from the induction of enzymes required for homologous recombination, or the production of substrate sites for recombination containing regions of DNA damage. We utilized split-dose experiments to investigate the induction of proteins required for survival, gene conversion, and mutation in a diploid strain of S. cerevisiae. We demonstrate that inducing doses of UV irradiation followed by a 6 h period of incubation render the cells resistant to challenge doses of UV irradiation. The effects of inducing and challenge doses of UV irradiation upon interchromosomal gene conversion and mutation are strictly additive. Using the yeast URA3 gene cloned in non-replicating single- and double-stranded plasmid vectors that integrate into chromosomal genes upon transformation, we show that UV irradiation of haploid yeast cells and homologous plasmid DNA sequences each stimulate homologous recombination approximately two-fold, and that these effects are additive. Non-specific DNA damage has little effect on the stimulation of homologous recombination, as shown by studies in which UV-irradiated heterologous DNA was included in transformation/recombination experiments. We further demonstrate that the effect of competing single- and double-stranded heterologous DNA sequences differs in UV-irradiated and unirradiated cells, suggesting an induction of recombinational machinery in UV-irradiated S. cerevisiae cells.

Collectivism and the meaning of suffering.

Science.gov (United States)

Sullivan, Daniel; Landau, Mark J; Kay, Aaron C; Rothschild, Zachary K

2012-12-01

People need to understand why an instance of suffering occurred and what purpose it might have. One widespread account of suffering is a repressive suffering construal (RSC): interpreting suffering as occurring because people deviate from social norms and as having the purpose of reinforcing the social order. Based on the theorizing of Emile Durkheim and others, we propose that RSC is associated with social morality-the belief that society dictates morality-and is encouraged by collectivist (as opposed to individualist) sentiments. Study 1 showed that dispositional collectivism predicts both social morality and RSC. Studies 2-4 showed that priming collectivist (vs. individualist) self-construal increases RSC of various types of suffering and that this effect is mediated by increased social morality (Study 4). Study 5 examined behavioral intentions, demonstrating that parents primed with a collectivist self-construal interpreted children's suffering more repressively and showed greater support for corporal punishment of children. (PsycINFO Database Record (c) 2012 APA, all rights reserved).

Saccharomyces boulardii Preserves the Barrier Function and Modulates the Signal Transduction Pathway Induced in Enteropathogenic Escherichia coli-Infected T84 Cells

Science.gov (United States)

Czerucka, Dorota; Dahan, Stephanie; Mograbi, Baharia; Rossi, Bernard; Rampal, Patrick

2000-01-01

Use of the nonpathogenic yeast Saccharomyces boulardii in the treatment of infectious diarrhea has attracted growing interest. The present study designed to investigate the effect of this yeast on enteropathogenic Escherichia coli (EPEC)-associated disease demonstrates that S. boulardii abrogated the alterations induced by an EPEC strain on transepithelial resistance, [3H]inulin flux, and ZO-1 distribution in T84 cells. Moreover, EPEC-mediated apoptosis of epithelial cells was delayed in the presence of S. boulardii. The yeast did not modify the number of adherent bacteria but lowered by 50% the number of intracellular bacteria. Infection by EPEC induced tyrosine phosphorylation of several proteins in T84 cells, including p46 and p52 SHC isoforms, that was attenuated in the presence of S. boulardii. Similarly, EPEC-induced activation of the ERK1/2 mitogen-activated protein (MAP) kinase pathway was diminished in the presence of the yeast. Interestingly, inhibition of the ERK1/2 pathway with the specific inhibitor PD 98059 decreased EPEC internalization, suggesting that modulation of the ERK1/2 MAP pathway might account for the lowering of the number of intracellular bacteria observed in the presence of S. boulardii. Altogether, this study demonstrated that S. boulardii exerts a protective effect on epithelial cells after EPEC adhesion by modulating the signaling pathway induced by bacterial infection. PMID:10992512

Enological characterization of Spanish Saccharomyces kudriavzevii strains, one of the closest relatives to parental strains of winemaking and brewing Saccharomyces cerevisiae × S. kudriavzevii hybrids.

Science.gov (United States)

Peris, D; Pérez-Través, L; Belloch, C; Querol, A

2016-02-01

Wine fermentation and innovation have focused mostly on Saccharomyces cerevisiae strains. However, recent studies have shown that other Saccharomyces species can also be involved in wine fermentation or are useful for wine bouquet, such as Saccharomyces uvarum and Saccharomyces paradoxus. Many interspecies hybrids have also been isolated from wine fermentation, such as S. cerevisiae × Saccharomyces kudriavzevii hybrids. In this study, we explored the genetic diversity and fermentation performance of Spanish S. kudriavzevii strains, which we compared to other S. kudriavzevii strains. Fermentations of red and white grape musts were performed, and the phenotypic differences between Spanish S. kudriavzevii strains under different temperature conditions were examined. An ANOVA analysis suggested striking similarity between strains for glycerol and ethanol production, although a high diversity of aromatic profiles among fermentations was found. The sources of these phenotypic differences are not well understood and require further investigation. Although the Spanish S. kudriavzevii strains showed desirable properties, particularly must fermentations, the quality of their wines was no better than those produced with a commercial S. cerevisiae. We suggest hybridization or directed evolution as methods to improve and innovate wine. Copyright © 2015 Elsevier Ltd. All rights reserved.

Direct conversion of starch to ethanol using recombınant Saccharomyces cerevisiae containing glucoamylase gene

Science.gov (United States)

Purkan, P.; Baktir, A.; Puspaningsih, N. N. T.; Ni'mah, M.

2017-09-01

Saccharomyces cerevisiae is known for its high fermentative capacity, high ethanol yield and its high ethanol tolerance. The yeast is inability converting starch (relatively inexpensive substrate) into biofuel ethanol. Insertion of glucoamylase gene in yeast cell of Saccharomyces cerevisiae had been done to increase the yeast function in ethanol fermentation from starch. Transformation of yeast of S. cerevisiae with recombinant plasmid yEP-GLO1 carrying gene encoding glucoamylase (GLO1) produced the recombinant yeast which enable to degrade starch. Optimizing of bioconversion process of starch into ethanol by the yeast of recombinant Saccharomyces cerevisiae [yEP-GLO1] had been also done. Starch concentration which could be digested by recombinant yeast of S. cerevisiae [yEP-GLO1] was 10% (w/v). Bioconversion of starch having concentration 10% (b/v) using recombinant yeast of S. cerevisiae BY5207 [yEP-GLO1] could result ethanol as 20% (v/v) to alcoholmeter and 19,5% (v/v) to gas of chromatography. Otherwise, using recombinant yeast S. cerevisiae S. cerevisiae AS3324 [yEP-GLO1] resulted ethanol as 17% (v/v) to alcoholmeter and 17,5% (v/v) to gas of chromatography. The highest ethanol in starch bioconversion using both recombinant yeasts BY5207 and AS3324 could be resulted on 144 hours of fermentation time as well as in pH 5.

Engineering the fatty acid metabolic pathway in Saccharomyces cerevisiae for advanced biofuel production

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Xiaoling Tang

2015-12-01

Full Text Available Fatty acid-derived fuels and chemicals have attracted a great deal of attention in recent decades, due to their following properties of high compatibility to gasoline-based fuels and existing infrastructure for their direct utilization, storage and distribution. The yeast Saccharomyces cerevisiae is the ideal biofuel producing candidate, based on the wealth of available genetic information and versatile tools designed to manipulate its metabolic pathways. Engineering the fatty acid metabolic pathways in S. cerevisiae is an effective strategy to increase its fatty acid biosynthesis and provide more pathway precursors for production of targeted products. This review summarizes the recent progress in metabolic engineering of yeast cells for fatty acids and fatty acid derivatives production, including the regulation of acetyl-CoA biosynthesis, NADPH production, fatty acid elongation, and the accumulation of activated precursors of fatty acids for converting enzymes. By introducing specific enzymes in the engineered strains, a powerful platform with a scalable, controllable and economic route for advanced biofuel production has been established. Keywords: Metabolic engineering, Fatty acid biosynthesis, Fatty acid derivatives, Saccharomyces cerevisiae

Improved ethanol tolerance of Saccharomyces cerevisiae in mixed cultures with Kluyveromyces lactis on high-sugar fermentation.

Science.gov (United States)

Yamaoka, Chizuru; Kurita, Osamu; Kubo, Tomoko

2014-12-01

The influence of non-Saccharomyces yeast, Kluyveromyces lactis, on metabolite formation and the ethanol tolerance of Saccharomyces cerevisiae in mixed cultures was examined on synthetic minimal medium containing 20% glucose. In the late stage of fermentation after the complete death of K. lactis, S. cerevisiae in mixed cultures was more ethanol-tolerant than that in pure culture. The chronological life span of S. cerevisiae was shorter in pure culture than mixed cultures. The yeast cells of the late stationary phase both in pure and mixed cultures had a low buoyant density with no significant difference in the non-quiescence state between both cultures. In mixed cultures, the glycerol contents increased and the alanine contents decreased when compared with the pure culture of S. cerevisiae. The distinctive intracellular amino acid pool concerning its amino acid concentrations and its amino acid composition was observed in yeast cells with different ethanol tolerance in the death phase. Co-cultivation of K. lactis seems to prompt S. cerevisiae to be ethanol tolerant by forming opportune metabolites such as glycerol and alanine and/or changing the intracellular amino acid pool. Copyright © 2014 Elsevier GmbH. All rights reserved.

Growth temperature exerts differential physiological and transcriptional responses in laboratory and wine strains of Saccharomyces cerevisiae

DEFF Research Database (Denmark)

Pizarra, Francisco J.; Jewett, Michael Christopher; Nielsen, Jens

2008-01-01

Laboratory strains of Saccharomyces cerevisiae have been widely used as a model for studying eukaryotic cells and mapping the molecular mechanisms of many different human diseases. Industrial wine yeasts, on the other hand, have been selected on the basis of their adaptation to stringent environm......Laboratory strains of Saccharomyces cerevisiae have been widely used as a model for studying eukaryotic cells and mapping the molecular mechanisms of many different human diseases. Industrial wine yeasts, on the other hand, have been selected on the basis of their adaptation to stringent...... environmental conditions and the organoleptic properties that they confer to wine. Here, we used a two-factor design to study the responses of a standard laboratory strain, CEN.PK113-7D, and an industrial wine yeast strain, EC1118, to growth temperatures of 15 degrees C and 30 degrees C in nitrogen......-limited, anaerobic, steady-state chemostat cultures. Physiological characterization revealed that the growth temperature strongly impacted the biomass yield of both strains. Moreover, we found that the wine yeast was better adapted to mobilizing resources for biomass production and that the laboratory yeast...

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.

Decarboxilase activity and biosynthetic processes in Saccharomyces carlsbergenesis upon the action of light

International Nuclear Information System (INIS)

Chebotarev, L.N.; Shaburova, G.V.; Licyuk, G.M.

1983-01-01

It is established that visible light of 410-520 nm wave-- lengths stimulated decarboxylase activity, protein biosynthesis and increase in the number of cells in the Saccharomyces carlsbergenesis yeast culture. A limiting link of these yeast metabolism is decarboxylizing of pyuvate providing the formation of a substrate for functioning of the di- and pericarboxilic acid cycle. The light effect can activate this process thus eliminating substrate deficiency of the Krebs cycle which results in the increase of anabolic processes intensity

Improved Xylose Metabolism by a CYC8 Mutant of Saccharomyces cerevisiae.

Science.gov (United States)

Nijland, Jeroen G; Shin, Hyun Yong; Boender, Leonie G M; de Waal, Paul P; Klaassen, Paul; Driessen, Arnold J M

2017-06-01

Engineering Saccharomyces cerevisiae for the utilization of pentose sugars is an important goal for the production of second-generation bioethanol and biochemicals. However, S. cerevisiae lacks specific pentose transporters, and in the presence of glucose, pentoses enter the cell inefficiently via endogenous hexose transporters (HXTs). By means of in vivo engineering, we have developed a quadruple hexokinase deletion mutant of S. cerevisiae that evolved into a strain that efficiently utilizes d-xylose in the presence of high d-glucose concentrations. A genome sequence analysis revealed a mutation (Y353C) in the general corepressor CYC8 , or SSN6 , which was found to be responsible for the phenotype when introduced individually in the nonevolved strain. A transcriptome analysis revealed altered expression of 95 genes in total, including genes involved in (i) hexose transport, (ii) maltose metabolism, (iii) cell wall function (mannoprotein family), and (iv) unknown functions (seripauperin multigene family). Of the 18 known HXTs, genes for 9 were upregulated, especially the low or nonexpressed HXT10 , HXT13 , HXT15 , and HXT16 Mutant cells showed increased uptake rates of d-xylose in the presence of d-glucose, as well as elevated maximum rates of metabolism ( V max ) for both d-glucose and d-xylose transport. The data suggest that the increased expression of multiple hexose transporters renders d-xylose metabolism less sensitive to d-glucose inhibition due to an elevated transport rate of d-xylose into the cell. IMPORTANCE The yeast Saccharomyces cerevisiae is used for second-generation bioethanol formation. However, growth on xylose is limited by pentose transport through the endogenous hexose transporters (HXTs), as uptake is outcompeted by the preferred substrate, glucose. Mutant strains were obtained with improved growth characteristics on xylose in the presence of glucose, and the mutations mapped to the regulator Cyc8. The inactivation of Cyc8 caused increased

The pde2 gene of Saccharomyces cerevisiae is allelic to rca1 and encodes a phosphodiesterase which protects the cell from extracellular cAMP.

Science.gov (United States)

Wilson, R B; Renault, G; Jacquet, M; Tatchell, K

1993-07-05

The high affinity cAMP phosphodiesterase, encoded by PDE2, is an important component of the cAMP-dependent protein kinase signaling system in Saccharomyces cerevisiae. An unexpected phenotype of pde2 mutants is sensitivity to external cAMP. This trait has been found independently for rca1 mutants and has been used to monitor the effects of cAMP on several biological processes. We demonstrate here that RCA1 is identical to PDE2. Further analysis of the phenotype of pde2 deletions reveal that exogenously added cAMP results in an increase in the internal level of cAMP. This increase slows down the rate of cell division by increasing the length of the G1 phase of the cell cycle and leads to increased cell volume. Also, cells with a disrupted PDE2 gene previously arrested by nutrient starvation rapidly lose thermotolerance when incubated with exogenous cAMP. From these observations we propose that a role of the PDE2-encoded phosphodiesterase may be to help insulate the internal cAMP pools from the external environment. This protective role might also be important in other eukaryotic organisms where cAMP is a key second messenger.

Non-Saccharomyces Yeasts Nitrogen Source Preferences: Impact on Sequential Fermentation and Wine Volatile Compounds Profile

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Antoine Gobert

2017-11-01

Full Text Available Nitrogen sources in the must are important for yeast metabolism, growth, and performance, and wine volatile compounds profile. Yeast assimilable nitrogen (YAN deficiencies in grape must are one of the main causes of stuck and sluggish fermentation. The nitrogen requirement of Saccharomyces cerevisiae metabolism has been described in detail. However, the YAN preferences of non-Saccharomyces yeasts remain unknown despite their increasingly widespread use in winemaking. Furthermore, the impact of nitrogen consumption by non-Saccharomyces yeasts on YAN availability, alcoholic performance and volatile compounds production by S. cerevisiae in sequential fermentation has been little studied. With a view to improving the use of non-Saccharomyces yeasts in winemaking, we studied the use of amino acids and ammonium by three strains of non-Saccharomyces yeasts (Starmerella bacillaris, Metschnikowia pulcherrima, and Pichia membranifaciens in grape juice. We first determined which nitrogen sources were preferentially used by these yeasts in pure cultures at 28 and 20°C (because few data are available. We then carried out sequential fermentations at 20°C with S. cerevisiae, to assess the impact of the non-Saccharomyces yeasts on the availability of assimilable nitrogen for S. cerevisiae. Finally, 22 volatile compounds were quantified in sequential fermentation and their levels compared with those in pure cultures of S. cerevisiae. We report here, for the first time, that non-Saccharomyces yeasts have specific amino-acid consumption profiles. Histidine, methionine, threonine, and tyrosine were not consumed by S. bacillaris, aspartic acid was assimilated very slowly by M. pulcherrima, and glutamine was not assimilated by P. membranifaciens. By contrast, cysteine appeared to be a preferred nitrogen source for all non-Saccharomyces yeasts. In sequential fermentation, these specific profiles of amino-acid consumption by non-Saccharomyces yeasts may account for

Non-Saccharomyces Yeasts Nitrogen Source Preferences: Impact on Sequential Fermentation and Wine Volatile Compounds Profile

Science.gov (United States)

Gobert, Antoine; Tourdot-Maréchal, Raphaëlle; Morge, Christophe; Sparrow, Céline; Liu, Youzhong; Quintanilla-Casas, Beatriz; Vichi, Stefania; Alexandre, Hervé

2017-01-01

Nitrogen sources in the must are important for yeast metabolism, growth, and performance, and wine volatile compounds profile. Yeast assimilable nitrogen (YAN) deficiencies in grape must are one of the main causes of stuck and sluggish fermentation. The nitrogen requirement of Saccharomyces cerevisiae metabolism has been described in detail. However, the YAN preferences of non-Saccharomyces yeasts remain unknown despite their increasingly widespread use in winemaking. Furthermore, the impact of nitrogen consumption by non-Saccharomyces yeasts on YAN availability, alcoholic performance and volatile compounds production by S. cerevisiae in sequential fermentation has been little studied. With a view to improving the use of non-Saccharomyces yeasts in winemaking, we studied the use of amino acids and ammonium by three strains of non-Saccharomyces yeasts (Starmerella bacillaris, Metschnikowia pulcherrima, and Pichia membranifaciens) in grape juice. We first determined which nitrogen sources were preferentially used by these yeasts in pure cultures at 28 and 20°C (because few data are available). We then carried out sequential fermentations at 20°C with S. cerevisiae, to assess the impact of the non-Saccharomyces yeasts on the availability of assimilable nitrogen for S. cerevisiae. Finally, 22 volatile compounds were quantified in sequential fermentation and their levels compared with those in pure cultures of S. cerevisiae. We report here, for the first time, that non-Saccharomyces yeasts have specific amino-acid consumption profiles. Histidine, methionine, threonine, and tyrosine were not consumed by S. bacillaris, aspartic acid was assimilated very slowly by M. pulcherrima, and glutamine was not assimilated by P. membranifaciens. By contrast, cysteine appeared to be a preferred nitrogen source for all non-Saccharomyces yeasts. In sequential fermentation, these specific profiles of amino-acid consumption by non-Saccharomyces yeasts may account for some of the

Importância da parede celular de levedura (Saccharomyces sp. como fonte de fibra na alimentação Importance of yeast (Saccharomyces cerevisiae cell wall as source of dietary fiber

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Eloísa A. PÁDUA

2000-08-01

Full Text Available O principal objetivo desta pesquisa foi estudar a influência da adição de 10% e 20% da fração parede celular de levedura (Saccharomyces sp., a uma dieta hipercolesterolêmica (5% gordura de coco mais 2% colesterol em ratos Wistar. A justificativa para o trabalho está relacionada com a quantidade crescente de levedura gerada como subproduto nas indústrias de álcool e de cerveja e o interesse na utilização de derivados de levedura como ingredientes funcionais em alimentação humana. Utilizou-se como padrão uma dieta de caseína (AIN-93G com 5% de celulose. Foram também utilizadas dietas hipercolesterolêmicas com 10 ou 20% de celulose, para comparação. Foram avaliados os índices: digestibilidade, valor biológico e utilização líquida aparentes da proteína, quociente de eficiência alimentar, velocidade de trânsito do conteúdo intestinal, comprimento do intestino delgado e as concentrações séricas de lipídios totais, triacilgliceróis e colesterol total. A fração parede celular, assim como a celulose provocaram uma diminuição da digestibilidade da proteína e do quociente de eficiência alimentar, mas não se observou influência no valor biológico da proteína e no ganho de peso. A adição de 10% ou 20%, tanto de parede celular como de celulose promoveu aumento da velocidade de trânsito do conteúdo intestinal e aumento no comprimento do intestino delgado. A fração parede celular nas concentrações de 10% (1° ensaio ou 20% (2° ensaio promoveu abaixamento nos níveis de triacilgliceróis séricos, contudo não influiu no abaixamento das concentrações de lipídios totais e de colesterol total.The main objective of this investigation was to study the influence of 10 and 20% addition of yeast (Saccharomyces sp. cell wall into a hypercholesterolemic (5% coconut fat plus 2% cholesterol diet, on Wistar rats. The work is justified by the increasing amount of yeast generated as byproduct of the alcohol and brewer

Mitochondrial genome evolution in the Saccharomyces sensu stricto complex.

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Ruan, Jiangxing; Cheng, Jian; Zhang, Tongcun; Jiang, Huifeng

2017-01-01

Exploring the evolutionary patterns of mitochondrial genomes is important for our understanding of the Saccharomyces sensu stricto (SSS) group, which is a model system for genomic evolution and ecological analysis. In this study, we first obtained the complete mitochondrial sequences of two important species, Saccharomyces mikatae and Saccharomyces kudriavzevii. We then compared the mitochondrial genomes in the SSS group with those of close relatives, and found that the non-coding regions evolved rapidly, including dramatic expansion of intergenic regions, fast evolution of introns and almost 20-fold higher rearrangement rates than those of the nuclear genomes. However, the coding regions, and especially the protein-coding genes, are more conserved than those in the nuclear genomes of the SSS group. The different evolutionary patterns of coding and non-coding regions in the mitochondrial and nuclear genomes may be related to the origin of the aerobic fermentation lifestyle in this group. Our analysis thus provides novel insights into the evolution of mitochondrial genomes.

PRODUKSI ETANOL DARI TETES TEBU OLEH Saccharomyces cerevisiae PEMBENTUK FLOK (NRRL – Y 265 (Ethanol Production from Cane Molasses by Flocculant Saccharomyces cerevisiae (NRRL – Y 265

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Agustin Krisna Wardani

2013-08-01

Full Text Available The potential use of sugar cane molasses by flocculant Saccharomyces cerevisiae in ethanol production was investigated. In order to minimize the negative effect of calcium on yeast growth, pretreated sugar cane molasses with dilute acid was performed. The influence of process parameters such as sugar concentration and inoculum concentration were evaluated for enhancing bioethanol production. Result showed that maximum ethanol concentration of 8,792% (b/v was obtained at the best condition of inoculum concentration 10% (v/v and sugar concentration 15% (b/v. Based on the experimental data, maximum yield of ethanol production of 65% was obtained. This result demonstrated the potential of molasses as promising biomass resources for ethanol production. Keywords: Ethanol, preteated cane molasses, flocculant Saccharomyces cerevisiae, fermentation   ABSTRAK Efisiensi produksi bioetanol diperoleh melalui ketepatan pemilihan jenis mikroorganisme, bahan baku, dan kontrol proses fermentasi. Alternatif proses untuk meminimalisasi biaya produksi etanol adalah dengan mengeliminasi tahap pemisahan sentrifugasi sel dari produk karena memerlukan biaya instalasi dan biaya perawatan yang tinggi. Proses sentrifugasi merupakan tahapan penting untuk memisahkan sel mikroba dari medium fermentasi pada produksi bioetanol. Untuk meminimalisir biaya produksi akibat proses tersebut digunakan inokulum Saccharomyces cerevisiae pembentuk flok dan tetes tebu sebagai sumber gula. Penelitian ini bertujuan untuk mendapatkan konsentrasi penambahan inokulum Saccharomyces cerevisiae pembentuk flok dan konsentrasi sumber gula dalam tetes tebu yang tepat dalam produksi etanol yang maksimum. Saccharomyces cerevisiae sebanyak 5%, 10%, dan 15% (v/v diinokulasikan pada medium tetes tebu hasil pretreatment dengan kandungan gula 15%, 20%, dan 25% (b/v pada pH 5. Fermentasi dilakukan pada suhu 30°C dan agitasi 100 rpm selama 72 jam. Etanol tertinggi didapat pada kondisi konsentrasi inokulum

Effect of menadione and hydrogen peroxide on catalase activity in Saccharomyces yeast strains

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Nadejda EFREMOVA

2013-05-01

Full Text Available It has been studied the possibility of utilization of two important oxidant factors as regulators of catalase activity in Saccharomyces yeasts. In this paper results of the screening of some Saccharomyces yeast strains for potential producers of catalase are presented. Results of the screening for potential catalase producer have revealed that Saccharomyces cerevisiae CNMN-Y-11 strain possesses the highest catalase activity (2900 U/mg protein compared with other samples. Maximum increase of catalase activity with 50-60% compared to the reference sample was established in the case of hydrogen peroxide and menadione utilization in optimal concentrations of 15 and 10 mM. This research has been demonstrated the potential benefits of application of hydrogen peroxide and menadione as stimulatory factors of catalase activity in Saccharomyces yeasts.

Two homologous genes, DCW1 (YKL046c) and DFG5, are essential for cell growth and encode glycosylphosphatidylinositol (GPI)-anchored membrane proteins required for cell wall biogenesis in Saccharomyces cerevisiae.

Science.gov (United States)

Kitagaki, Hiroshi; Wu, Hong; Shimoi, Hitoshi; Ito, Kiyoshi

2002-11-01

The cell wall of Saccharomyces cerevisiae consists of glucan, chitin and various kinds of mannoproteins. Major parts of mannoproteins are synthesized as glycosylphosphatidylinositol (GPI)-anchored proteins and are then transferred to cell wall beta-1,6-glucan. A glycosyltransferase has been hypothesized to catalyse this transfer reaction. A database search revealed that the products of YKL046c and DFG5 are homologous to bacterial mannosidase. These genes are homologous to each other and have primary structures characteristic of GPI-anchored proteins. Although single disruptants of ykl046c and dfg5 were viable, ykl046cDelta was hypersensitive to a cell wall-digesting enzyme (zymolyase), suggesting that this gene is involved in cell wall biosynthesis. We therefore designated this gene as DCW1 (defective cell wall). A double disruptant of dcw1 and dfg5 was synthetically lethal, indicating that the functions of these gene products are redundant, and at least one of them is required for cell growth. Cells deficient in both Dcw1p and Dfg5p were round and large, had cell walls that contained an increased amount of chitin and secreted a major cell wall protein, Cwp1p, into the medium. Biochemical analyses showed that epitope-tagged Dcw1p is an N-glycosylated, GPI-anchored membrane protein and is localized in the membrane fraction including the cell surface. These results suggest that both Dcw1p and Dfg5p are GPI-anchored membrane proteins and are required for normal biosynthesis of the cell wall.

The Use of Mixed Populations of Saccharomyces cerevisiae and S. kudriavzevii to Reduce Ethanol Content in Wine: Limited Aeration, Inoculum Proportions, and Sequential Inoculation

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Javier Alonso-del-Real

2017-10-01

Full Text Available Saccharomyces cerevisiae is the most widespread microorganism responsible for wine alcoholic fermentation. Nevertheless, the wine industry is currently facing new challenges, some of them associate with climate change, which have a negative effect on ethanol content and wine quality. Numerous and varied strategies have been carried out to overcome these concerns. From a biotechnological point of view, the use of alternative non-Saccharomyces yeasts, yielding lower ethanol concentrations and sometimes giving rise to new and interesting aroma, is one of the trendiest approaches. However, S. cerevisiae usually outcompetes other Saccharomyces species due to its better adaptation to the fermentative environment. For this reason, we studied for the first time the use of a Saccharomyces kudriavzevii strain, CR85, for co-inoculations at increasing proportions and sequential inoculations, as well as the effect of aeration, to improve its fermentation performance in order to obtain wines with an ethanol yield reduction. An enhanced competitive performance of S. kudriavzevii CR85 was observed when it represented 90% of the cells present in the inoculum. Furthermore, airflow supply of 20 VVH to the fermentation synergistically improved CR85 endurance and, interestingly, a significant ethanol concentration reduction was achieved.

Construction of a novel kind of expression plasmid by homologous recombination in Saccharomyces cerevisiae

Institute of Scientific and Technical Information of China (English)

CHEN; Xiangling

2005-01-01

(2): 91―96.[13]Hong, M., Sam, K., Peter, J. S. et al., Plasmid construction by homologous recombination in yeast, Gene, 1987, 58: 201―216.[14]Prado, F., Aguilera, A., New in-vivo cloning methods, methods by homologous recombination in yeast, Curr. Genet., 1994, 20: 180―183.[15]Jacques, D., DNA insertion system for complex yeast shuttle vectors, Curr. Genet., 1995, 27: 309―311.[16]Erik, D., Bruno, D., Mireille, D. et al., In vivo cloning by homologous recombination in yeast using a two-plasmid-based system, Yeast, 1995, 11: 629―640.[17]Kevin, R. O., Kham, T. V., Susan, M., Chris, P., Recombination-mediated PCR-directed plasmid construction in vivo in yeast, Nucleic Acids Res., 1997, 25(2): 451―452.[18]Falco, S. C., Li, Y. Y., James, R. B., David, B., Genetic properties of chromosomally integrated 2μ plasmid DNA in yeast, Cell, 1982, 29: 573―584.[19]Francesca, S. L., Kevtn, L., Michael, A. R., In vivo site-directed mutagenesis using oligonucleotides, Nature Biotechnology, 2001, 19: 773―776.[20]Chulman, J., Hyuck, K., Sangmee, A. J., In vivo site-directed mutagenesis of yeast plasmids using a three-fragment homologous recombination system, Biotechniques, 2002, 33(2): 288―294.[21]Wach, A., Brachat, A., Pohlmann, R., Philippsen, P., New heterologus modules for classical or PCR-based gene disruption in Saccharomyces cerevisiea, Yeast, 1994, 10: 1793―1808.[22]Lorenz, M. C., Muir, R. S., Lim, E. et al., Gene disruption with PCR products in Saccharomyces cerevisiae, Gene, 1995, 158: 113―117.[23]Bhargava, J., Direct cloning of genomic DNA by recombinogenic targeting method using a yeast-bacterial shuttle vector, pClasper, Genomics, 1999, 62: 285―288.[24]Sambrook, J., Fritsch, E. F., Maniatis, T., Molecular Cloning: A Laboratory Manual, New York: Cold Spring Harbor Laboratory Press, 1989.[25]Gietz, R. D., Schiestl, R. H., Williems, A. R. et al., Studies on the transformation of intact yeast cells by the LiAc/SS-DNA/PEG procedure, Yeast, 1995, 11(4): 355�

Genetic Approaches to Study Meiosis and Meiosis-Specific Gene Expression in Saccharomyces cerevisiae.

Science.gov (United States)

Kassir, Yona; Stuart, David T

2017-01-01

The budding yeast Saccharomyces cerevisiae has a long history as a model organism for studies of meiosis and the cell cycle. The popularity of this yeast as a model is in large part due to the variety of genetic and cytological approaches that can be effectively performed with the cells. Cultures of the cells can be induced to synchronously progress through meiosis and sporulation allowing large-scale gene expression and biochemical studies to be performed. Additionally, the spore tetrads resulting from meiosis make it possible to characterize the haploid products of meiosis allowing investigation of meiotic recombination and chromosome segregation. Here we describe genetic methods for analysis progression of S. cerevisiae through meiosis and sporulation with an emphasis on strategies for the genetic analysis of regulators of meiosis-specific genes.

Saccharomyces cerevisiae biofilm tolerance towards systemic antifungals depends on growth phase

DEFF Research Database (Denmark)

Bojsen, Rasmus Kenneth; Regenberg, Birgitte; Folkesson, Sven Anders

2014-01-01

Background : Biofilm-forming Candida species cause infections that can be difficult to eradicate, possibly because of antifungal drug tolerance mechanisms specific to biofilms. In spite of decades of research, the connection between biofilm and drug tolerance is not fully understood. Results : We...... used Saccharomyces cerevisiae as a model for drug susceptibility of yeast biofilms. Confocal laser scanning microscopy showed that S. cerevisiae and C. glabrata form similarly structured biofilms and that the viable cell numbers were significantly reduced by treatment of mature biofilms...... with amphotericin B but not voriconazole, flucytosine, or caspofungin. We showed that metabolic activity in yeast biofilm cells decreased with time, as visualized by FUN-1 staining, and mature, 48-hour biofilms contained cells with slow metabolism and limited growth. Time-kill studies showed that in exponentially...

Cell surface engineering of Saccharomyces cerevisiae combined with membrane separation technology for xylitol production from rice straw hydrolysate.

Science.gov (United States)

Guirimand, Gregory; Sasaki, Kengo; Inokuma, Kentaro; Bamba, Takahiro; Hasunuma, Tomohisa; Kondo, Akihiko

2016-04-01

Xylitol, a value-added polyol deriving from D-xylose, is widely used in both the food and pharmaceutical industries. Despite extensive studies aiming to streamline the production of xylitol, the manufacturing cost of this product remains high while demand is constantly growing worldwide. Biotechnological production of xylitol from lignocellulosic waste may constitute an advantageous and sustainable option to address this issue. However, to date, there have been few reports of biomass conversion to xylitol. In the present study, xylitol was directly produced from rice straw hydrolysate using a recombinant Saccharomyces cerevisiae YPH499 strain expressing cytosolic xylose reductase (XR), along with β-glucosidase (BGL), xylosidase (XYL), and xylanase (XYN) enzymes (co-)displayed on the cell surface; xylitol production by this strain did not require addition of any commercial enzymes. All of these enzymes contributed to the consolidated bioprocessing (CBP) of the lignocellulosic hydrolysate to xylitol to produce 5.8 g/L xylitol with 79.5 % of theoretical yield from xylose contained in the biomass. Furthermore, nanofiltration of the rice straw hydrolysate provided removal of fermentation inhibitors while simultaneously increasing sugar concentrations, facilitating high concentration xylitol production (37.9 g/L) in the CBP. This study is the first report (to our knowledge) of the combination of cell surface engineering approach and membrane separation technology for xylitol production, which could be extended to further industrial applications.

Induction of spontaneous and UV-induced mutations during commitment to meiosis in Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Machida, I.; Nakai, S.

1980-01-01

Inductions of reversions of nonsense, missense and frameshift-type mutations were investigated in a diploid cell population of Saccharomyces cerevisiae during commitment to meiosis, by using the medium-transfer technique from sporulation medium to vegetative medium. The yields of spontaneous reverse mutations obtained from the cells that were committed to different stages during meiosis were rather constant irrespective of the alleles tested, although the yields of both intergenic and intragenic recombinations markedly increased. The susceptibilities to UV-induced reverse mutations examined during commitment to meiosis were not changed appreciably. It is concluded that induction of base-change-type mutations in meiosis is not essentially different from that in mitosis. (orig.)

Adsorption of Saccharomyces cerevisiae onto cellulose and ecteola-cellulose films for ethanol production

Energy Technology Data Exchange (ETDEWEB)

Lueng, K.L.; Joshi, S.; Yamazaki, H.

1983-05-01

Epichlorohydrin-triethanolamine (ECTEOLA)-cellulose films (paper and cloth) have been found to bind Saccharomyces cerevisiae cells which were able to develop metabolically active colonies on the surface of the films. Umodified cellulose films also bound the yeast but to a lesser extent. Film fermenters were constructed by coiling a double layer of the cloth and copper screen and vertically placing the resulting cartridge into a column. These film fermenters were able to convert the sugars (14%) in the hydrolysate of a Jerusalem artichoke tuber into ethanol, with 90% of the theoretical yield after 6 hours of fermentation. The bound yeast produced ethanol at a specific rate of 1.0 g ethanol per g cell per hour. (Refs. 4).

Hybridization and adaptive evolution of diverse Saccharomyces species for cellulosic biofuel production.

Science.gov (United States)

Peris, David; Moriarty, Ryan V; Alexander, William G; Baker, EmilyClare; Sylvester, Kayla; Sardi, Maria; Langdon, Quinn K; Libkind, Diego; Wang, Qi-Ming; Bai, Feng-Yan; Leducq, Jean-Baptiste; Charron, Guillaume; Landry, Christian R; Sampaio, José Paulo; Gonçalves, Paula; Hyma, Katie E; Fay, Justin C; Sato, Trey K; Hittinger, Chris Todd

2017-01-01

Lignocellulosic biomass is a common resource across the globe, and its fermentation offers a promising option for generating renewable liquid transportation fuels. The deconstruction of lignocellulosic biomass releases sugars that can be fermented by microbes, but these processes also produce fermentation inhibitors, such as aromatic acids and aldehydes. Several research projects have investigated lignocellulosic biomass fermentation by the baker's yeast Saccharomyces cerevisiae . Most projects have taken synthetic biological approaches or have explored naturally occurring diversity in S. cerevisiae to enhance stress tolerance, xylose consumption, or ethanol production. Despite these efforts, improved strains with new properties are needed. In other industrial processes, such as wine and beer fermentation, interspecies hybrids have combined important traits from multiple species, suggesting that interspecies hybridization may also offer potential for biofuel research. To investigate the efficacy of this approach for traits relevant to lignocellulosic biofuel production, we generated synthetic hybrids by crossing engineered xylose-fermenting strains of S. cerevisiae with wild strains from various Saccharomyces species. These interspecies hybrids retained important parental traits, such as xylose consumption and stress tolerance, while displaying intermediate kinetic parameters and, in some cases, heterosis (hybrid vigor). Next, we exposed them to adaptive evolution in ammonia fiber expansion-pretreated corn stover hydrolysate and recovered strains with improved fermentative traits. Genome sequencing showed that the genomes of these evolved synthetic hybrids underwent rearrangements, duplications, and deletions. To determine whether the genus Saccharomyces contains additional untapped potential, we screened a genetically diverse collection of more than 500 wild, non-engineered Saccharomyces isolates and uncovered a wide range of capabilities for traits relevant to

ISOTERMAS DE ADSORÇÃO DE CÁDMIO POR Saccharomyces cerevisiae ISOTHERMS OF CADMIUM ADSORPTION BY Saccharomyces cerevisae

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Silvana ALBERTINI

2001-08-01

Full Text Available Com o objetivo de determinar as isotermas de adsorção de cádmio por Saccharomyces cerevisiae, foram utilizados os sais cloreto e nitrato de cádmio nas concentrações de 5, 10, 20, 40, 60, 80 e 100mg L-1. A biomassa foi produzida a partir de uma cultura "starter"de Saccharomyces cerevisiae IZ 1904. Após o contato de 16h entre o microrganismo e as soluções em estudo, a biomassa foi separada por centrifugação e o teor de cádmio residual foi determinado no sobrenadante por espectrofotometria de absorção atômica. Para os dois sais empregados foi observado um acúmulo crescente de cádmio nas concentrações de 5, 10, 20 e 40mg L-1. Nas concentrações de 60, 80 e 100mg L-1 foi observado que a levedura acumulou teores menores do metal, evidenciando danos na parede celular, nem sempre acompanhados de iguais danos da membrana citoplasmática, tais alterações da parede visualizadas por microscopia eletrônica de varredura.With the objective of determining the isotherms of cadmium the adsorption by Saccharomyces cerevisiae, the chloride and nitrate salts were used in the concentrations of 5, 10, 20, 40, 60, 80, and 100mg L-1. The biomass was produced from a starter culture of Saccharomyces cerevisiae IZ 1904. After a 16h contact between the microrganism and solutions of study the biomass was separated by a centrifuge and the cadmium residue content was determined at the supernatant by atomic adsorption spectrophotometry. For the two salts used a growing accumulation of cadmium was observed at concentrations of 5, 10, 20, and 40mg L-1. In the concentrations of 60, 80 and 100mg L-1 a decreasing of the accumulation of the metal was observed, evidencing damages of the cellular wall, which they're not accompanied always by damages of the citoplasmatic membrane, visualized by scanning electron microscopy.

Jeast (Saccharomyces cerevisial) mutants with enhanced induced mutagenesis

International Nuclear Information System (INIS)

Ivanov, E.L.; Koval'tsova, S.V.; Korolev, V.G.

1987-01-01

The influence of him1-1, him2-1, him3-1 and himX mutations on induction frequency and specificity of UV-induced adenine-dependent mutations in the yeast Saccharomyces cerevisiae has been. Him mutations do not render haploid cells more sensitive to the lethal action of UV-light; however, in him strains adeine-dependent mutations (ade, ade2) were induced more frequently (1.5-2-fold), as compared to the HIM strain. An analysis of the molecular nature of ade2 mutants revealed than him1-1, him2-1, and himX mutations increase specifically the yield of transitions (AT-GC and GC→AT), whereas in the him3-1, strain the yield of transversions was enhanced as well. We suggest him mutations analysed to affect specific repair pathway for mismatch correction

C Terminus of Nce102 Determines the Structure and Function of Microdomains in the Saccharomyces cerevisiae Plasma Membrane

Czech Academy of Sciences Publication Activity Database

Loibl, M.; Grossmann, G.; Strádalová, Vendula; Klingl, A.; Rachel, R.; Tanner, W.; Malínský, Jan; Opekarová, Miroslava

2010-01-01

Roč. 9, č. 8 (2010), s. 1184-1192 ISSN 1535-9778 R&D Projects: GA ČR(CZ) GA204/07/0133; GA ČR(CZ) GC204/08/J024 Grant - others:GA ČR(CZ) GA204/09/1924; GA ČR(CZ) KAN200520801 Program:GA; IA Institutional research plan: CEZ:AV0Z50390703; CEZ:AV0Z50200510 Keywords : cell * endoplasmic-reticulum * Saccharomyces cerevisiae Subject RIV: EA - Cell Biology Impact factor: 3.395, year: 2010

Saccharomyces jurei sp. nov., isolation and genetic identification of a novel yeast species from Quercus robur.

Science.gov (United States)

Naseeb, Samina; James, Stephen A; Alsammar, Haya; Michaels, Christopher J; Gini, Beatrice; Nueno-Palop, Carmen; Bond, Christopher J; McGhie, Henry; Roberts, Ian N; Delneri, Daniela

2017-06-01

Two strains, D5088T and D5095, representing a novel yeast species belonging to the genus Saccharomyces were isolated from oak tree bark and surrounding soil located at an altitude of 1000 m above sea level in Saint Auban, France. Sequence analyses of the internal transcribed spacer (ITS) region and 26S rRNA D1/D2 domains indicated that the two strains were most closely related to Saccharomyces mikatae and Saccharomyces paradoxus. Genetic hybridization analyses showed that both strains are reproductively isolated from all other Saccharomyces species and, therefore, represent a distinct biological species. The species name Saccharomyces jurei sp. nov. is proposed to accommodate these two strains, with D5088T (=CBS 14759T=NCYC 3947T) designated as the type strain.

Many Saccharomyces cerevisiae Cell Wall Protein Encoding Genes Are Coregulated by Mss11, but Cellular Adhesion Phenotypes Appear Only Flo Protein Dependent.

Science.gov (United States)

Bester, Michael C; Jacobson, Dan; Bauer, Florian F

2012-01-01

The outer cell wall of the yeast Saccharomyces cerevisiae serves as the interface with the surrounding environment and directly affects cell-cell and cell-surface interactions. Many of these interactions are facilitated by specific adhesins that belong to the Flo protein family. Flo mannoproteins have been implicated in phenotypes such as flocculation, substrate adhesion, biofilm formation, and pseudohyphal growth. Genetic data strongly suggest that individual Flo proteins are responsible for many specific cellular adhesion phenotypes. However, it remains unclear whether such phenotypes are determined solely by the nature of the expressed FLO genes or rather as the result of a combination of FLO gene expression and other cell wall properties and cell wall proteins. Mss11 has been shown to be a central element of FLO1 and FLO11 gene regulation and acts together with the cAMP-PKA-dependent transcription factor Flo8. Here we use genome-wide transcription analysis to identify genes that are directly or indirectly regulated by Mss11. Interestingly, many of these genes encode cell wall mannoproteins, in particular, members of the TIR and DAN families. To examine whether these genes play a role in the adhesion properties associated with Mss11 expression, we assessed deletion mutants of these genes in wild-type and flo11Δ genetic backgrounds. This analysis shows that only FLO genes, in particular FLO1/10/11, appear to significantly impact on such phenotypes. Thus adhesion-related phenotypes are primarily dependent on the balance of FLO gene expression.

Study on biosorption of uranium by alginate immobilized saccharomyces cerevisiae

International Nuclear Information System (INIS)

Wang Baoe; Xu Weichang; Xie Shuibo; Guo Yangbin

2005-01-01

Saccharomyces cerevisiae has great capability of biosorption of uranium. The maxium uptake is 172.4 mg/g according to this study. To adapt to the application of the biomass in the field, the biosorption of uranium by cross-linked and alginate calcium immobilized Saccharomyces cerevisiae is studied. Results indicate the maxium uptake is 185.2 mg/g by formaldehyde cross-linked biomass, and it is 769.2 mg/g by alginate calcium immobilized biomass. (authors)

In vivo 31P nuclear magnetic resonance saturation transfer measurements of phosphate exchange reactions in the yeast Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Campbell, S.L.; Jones, K.A.; Schulman, R.G.

1985-01-01

31 P saturation transfer techniques have been used to measure phosphate kinetics in the yeast Saccharomyces cerevisiae. The phosphate comsumption rate observed in acetate grown mid-log cells was combined with measurements of O 2 consumption to yield P/O ratios of 2.2 and 2.9, for cells respiring on glucose and ethanol, respectively. However, no phosphate consumption activity was observed in saturation transfer experiments on anaerobic glucose fed cells. The phosphate consumption rates measured by saturation transfer in cells respiring on glucose and ethanol was attributed to the unidirectional rates of mitochondrial ATP synthesis. (Auth.)

CK2 activity is modulated by growth rate in Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Tripodi, Farida; Cirulli, Claudia; Reghellin, Veronica; Marin, Oriano; Brambilla, Luca; Schiappelli, Maria Patrizia; Porro, Danilo; Vanoni, Marco; Alberghina, Lilia; Coccetti, Paola

2010-01-01

Research highlights: → CK2 subunits are nuclear both in glucose and in ethanol growing yeast cells. → CK2 activity is modulated in S. cerevisiae. → CK2 activity is higher in conditions supporting higher growth rates. → V max is higher in faster growing cells, while K m is not affected. -- Abstract: CK2 is a highly conserved protein kinase controlling different cellular processes. It shows a higher activity in proliferating mammalian cells, in various types of cancer cell lines and tumors. The findings presented herein provide the first evidence of an in vivo modulation of CK2 activity, dependent on growth rate, in Saccharomyces cerevisiae. In fact, CK2 activity, assayed on nuclear extracts, is shown to increase in exponential growing batch cultures at faster growth rate, while localization of catalytic and regulatory subunits is not nutritionally modulated. Differences in intracellular CK2 activity of glucose- and ethanol-grown cells appear to depend on both increase in molecule number and k cat . Also in chemostat cultures nuclear CK2 activity is higher in faster growing cells providing the first unequivocal demonstration that growth rate itself can affect CK2 activity in a eukaryotic organism.

Ecological interactions among Saccharomyces cerevisiae strains: insight into the dominance phenomenon.

Science.gov (United States)

Pérez-Torrado, Roberto; Rantsiou, Kalliopi; Perrone, Benedeta; Navarro-Tapia, Elisabeth; Querol, Amparo; Cocolin, Luca

2017-03-07

This study investigates the behaviour of Saccharomyces cerevisiae strains, in order to obtain insight into the intraspecies competition taking place in mixed populations of this species. Two strains of S. cerevisiae, one dominant and one non-dominant, were labelled and mixed, and individual fermentations were set up to study the transcriptomes of the strains by means of RNA-seq. The results obtained suggest that cell-to-cell contact and aggregation, which are driven by the expression of genes that are associated with the cell surface, are indispensable conditions for the achievement of dominance. Observations on mixed aggregates, made up of cells of both strains, which were detected by means of flow cytometry, have confirmed the transcriptomic data. Furthermore, overexpression of the SSU1 gene, which encodes for a transporter that confers resistance to sulphites, provides an ecological advantage to the dominant strain. A mechanistic model is proposed that sheds light on the dominance phenomenon between different strains of the S. cerevisiae species. The collected data suggest that cell-to-cell contact, together with differential sulphite production and resistance is important in determining the dominance of one strain over another.

Enhanced pathway efficiency of Saccharomyces cerevisiae by introducing thermo-tolerant devices.

Science.gov (United States)

Liu, Yueqin; Zhang, Genli; Sun, Huan; Sun, Xiangying; Jiang, Nisi; Rasool, Aamir; Lin, Zhanglin; Li, Chun

2014-10-01

In this study, thermo-tolerant devices consisting of heat shock genes from thermophiles were designed and introduced into Saccharomyces cerevisiae for improving its thermo-tolerance. Among ten engineered thermo-tolerant yeasts, T.te-TTE2469, T.te-GroS2 and T.te-IbpA displayed over 25% increased cell density and 1.5-4-fold cell viability compared with the control. Physiological characteristics of thermo-tolerant strains revealed that better cell wall integrity, higher trehalose content and enhanced metabolic energy were preserved by thermo-tolerant devices. Engineered thermo-tolerant strain was used to investigate the impact of thermo-tolerant device on pathway efficiency by introducing β-amyrin synthesis pathway, showed 28.1% increased β-amyrin titer, 28-35°C broadened growth temperature range and 72h shortened fermentation period. The results indicated that implanting heat shock proteins from thermophiles to S. cerevisiae would be an efficient approach to improve its thermo-tolerance. Copyright © 2014 Elsevier Ltd. All rights reserved.

Analysis of the biological effects of a non-thermal plasma on saccharomyces cerevisiae

International Nuclear Information System (INIS)

Park, Gyung S.; Baik, Ku Y.; Kim, Jung G.; Kim, Yun J.; Lee, Kyung A.; Jung, Ran J.; Cho, Guang S.

2012-01-01

The cellular and the molecular responses of eukaryotic yeast (Saccharomyces cerevisiae) to a non-thermal plasma at atmospheric pressure are analyzed. A plasma device with a dielectric barrier discharge is used in order to understand the mechanisms of the plasma action on eukaryotic microbes. When the yeast cells are exposed to a plasma (at a 2-mm distance) and then cultured on a YPD (yeast extract, peptone, and dextrose) - agar plate, the number of surviving cells is reduced over exposure time. More than a 50% reduction in number is observed after two exposures of 5 minutes' duration. In addition, very small whitish colonies appear after the two exposures. The microscopic analysis indicates that the yeast cells treated with this plasma exposure have rough and shrunken shapes in comparison to the oval shapes with smooth surfaces of the control cells. The profile of proteins analyzed by using 2-dimentional electrophoresis demonstrates that the level of proteins with high molecular weights is increased in plasma-treated cells.

Production of a heterologous proteinase A by Saccharomyces kluyveri

DEFF Research Database (Denmark)

Møller, Kasper; Tidemand, L.D.; Winther, J.R.

2001-01-01

In order to evaluate the potential of Saccharomyces kluyveri for heterologous protein production, S. kluyveri Y159 was transformed with a S. cerevisiae-based multi-copy plasmid containing the S. cerevisiae PEP4 gene, which encodes proteinase A, under the control of its native promoter. As a refer......In order to evaluate the potential of Saccharomyces kluyveri for heterologous protein production, S. kluyveri Y159 was transformed with a S. cerevisiae-based multi-copy plasmid containing the S. cerevisiae PEP4 gene, which encodes proteinase A, under the control of its native promoter...

The Saccharomyces Genome Database Variant Viewer.

Science.gov (United States)

Sheppard, Travis K; Hitz, Benjamin C; Engel, Stacia R; Song, Giltae; Balakrishnan, Rama; Binkley, Gail; Costanzo, Maria C; Dalusag, Kyla S; Demeter, Janos; Hellerstedt, Sage T; Karra, Kalpana; Nash, Robert S; Paskov, Kelley M; Skrzypek, Marek S; Weng, Shuai; Wong, Edith D; Cherry, J Michael

2016-01-04

The Saccharomyces Genome Database (SGD; http://www.yeastgenome.org) is the authoritative community resource for the Saccharomyces cerevisiae reference genome sequence and its annotation. In recent years, we have moved toward increased representation of sequence variation and allelic differences within S. cerevisiae. The publication of numerous additional genomes has motivated the creation of new tools for their annotation and analysis. Here we present the Variant Viewer: a dynamic open-source web application for the visualization of genomic and proteomic differences. Multiple sequence alignments have been constructed across high quality genome sequences from 11 different S. cerevisiae strains and stored in the SGD. The alignments and summaries are encoded in JSON and used to create a two-tiered dynamic view of the budding yeast pan-genome, available at http://www.yeastgenome.org/variant-viewer. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

GOD AND THE SUFFERING OF HIS PEOPLE

African Journals Online (AJOL)

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Philosophically the problem of suffering gives a rational ... and adds that, the only legitimate response to .... can give ourselves in times of suffering is that ... Emotionally, people suffer hurt inside, ... death, and the evils that affect our world,.

Lycopene overproduction in Saccharomyces cerevisiae through combining pathway engineering with host engineering.

Science.gov (United States)

Chen, Yan; Xiao, Wenhai; Wang, Ying; Liu, Hong; Li, Xia; Yuan, Yingjin

2016-06-21

Microbial production of lycopene, a commercially and medically important compound, has received increasing concern in recent years. Saccharomyces cerevisiae is regarded as a safer host for lycopene production than Escherichia coli. However, to date, the lycopene yield (mg/g DCW) in S. cerevisiae was lower than that in E. coli and did not facilitate downstream extraction process, which might be attributed to the incompatibility between host cell and heterologous pathway. Therefore, to achieve lycopene overproduction in S. cerevisiae, both host cell and heterologous pathway should be delicately engineered. In this study, lycopene biosynthesis pathway was constructed by integration of CrtE, CrtB and CrtI in S. cerevisiae CEN.PK2. When YPL062W, a distant genetic locus, was deleted, little acetate was accumulated and approximately 100 % increase in cytosolic acetyl-CoA pool was achieved relative to that in parental strain. Through screening CrtE, CrtB and CrtI from diverse species, an optimal carotenogenic enzyme combination was obtained, and CrtI from Blakeslea trispora (BtCrtI) was found to have excellent performance on lycopene production as well as lycopene proportion in carotenoid. Then, the expression level of BtCrtI was fine-tuned and the effect of cell mating types was also evaluated. Finally, potential distant genetic targets (YJL064W, ROX1, and DOS2) were deleted and a stress-responsive transcription factor INO2 was also up-regulated. Through the above modifications between host cell and carotenogenic pathway, lycopene yield was increased by approximately 22-fold (from 2.43 to 54.63 mg/g DCW). Eventually, in fed-batch fermentation, lycopene production reached 55.56 mg/g DCW, which is the highest reported yield in yeasts. Saccharomyces cerevisiae was engineered to produce lycopene in this study. Through combining host engineering (distant genetic loci and cell mating types) with pathway engineering (enzyme screening and gene fine-tuning), lycopene yield was

Production of 3-hydroxypropionic acid from glucose and xylose by metabolically engineered Saccharomyces cerevisiae

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Kanchana R. Kildegaard

2015-12-01

Full Text Available Biomass, the most abundant carbon source on the planet, may in the future become the primary feedstock for production of fuels and chemicals, replacing fossil feedstocks. This will, however, require development of cell factories that can convert both C6 and C5 sugars present in lignocellulosic biomass into the products of interest. We engineered Saccharomyces cerevisiae for production of 3-hydroxypropionic acid (3HP, a potential building block for acrylates, from glucose and xylose. We introduced the 3HP biosynthetic pathways via malonyl-CoA or β-alanine intermediates into a xylose-consuming yeast. Using controlled fed-batch cultivation, we obtained 7.37±0.17 g 3HP L−1 in 120 hours with an overall yield of 29±1% Cmol 3HP Cmol−1 xylose. This study is the first demonstration of the potential of using S. cerevisiae for production of 3HP from the biomass sugar xylose. Keywords: Metabolic engineering, Biorefineries, 3-hydroxypropionic acid, Saccharomyces cerevisiae, Xylose utilization

[Saccharomyces boulardii modulates dendritic cell properties and intestinal microbiota disruption after antibiotic treatment].

Science.gov (United States)

Collignon, A; Sandré, C; Barc, M-C

2010-09-01

Saccharomyces boulardii is a non-pathogenic yeast with biotherapeutic properties that has been used successfully to prevent and to treat various infectious and antibiotic-associated diarrheas. The intestinal microbiota is responsible for colonization resistance and immune response to pathogens but can be disrupted by antibiotics and lose its barrier effect. Dendritic cells (DCs) are professional antigen-presenting cells of the immune system with the ability to initiate a primary immune response or immune tolerance. In a human microbiota-associated mouse model, we evaluated the influence of S. boulardii on the composition of the microbiota and on the properties of dendritic cells in normal homeostatic conditions and after antibiotic-induced stress. The DCs were derived from splenic precursors. Membrane antigen expression and phagocytosis of FITC-latex beads by DCs were evaluated by flow cytometry. The molecular analysis of the microbiota was performed with fluorescence in situ hybridization (FISH) combined with flow cytometry or confocal microscopy using group specific 16S rRNA targeted probes. This evaluation was conducted during and after a 7-day oral treatment with amoxicillin-clavulanic acid alone and in combination with the administration of the yeast. The antibiotic treatment increased the phagocytic activity of DCs. Their antigen presenting function (MHC class II antigen and CD 86 costimulatory molecule membrane expression) was up-regulated. This reflects a functional activation of DCs. In the presence of S. boulardii, the modification of membrane antigen expression was down regulated. To correlate these modifications to the microbiota disruption, we analyzed in parallel the composition of the intestinal microbiota. As previously shown, the amoxicillin-clavulanic acid treatment, both alone and with S. boulardii, did not quantitatively alter the total microbiota. In contrast, after one day of the antibiotic treatment the Clostridium coccoides group decreased

Repair of UV-irradiated plasmid DNA in excision repair deficient mutants of Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Ikai, K.; Tano, K.; Ohnishi, T.; Nozu, K.

1985-01-01

The repair of UV-irradiated DNA of plasmid YEp13 was studied in the incision defective strains by measurement of cell transformation frequency. In Saccharomyces cerevisiae, rad1,2,3 and 4 mutants could repair UV-damaged plasmid DNA. In Escherichia coli, uvrA mutant was unable to repair UV-damaged plasmid DNA; however, pretreatment of the plasmid with Micrococcus luteus endonuclease increased repair. It was concluded that all the mutations of yeast were probably limited only to the nuclear DNA. (author)

Influence the oxidant action of selenium in radiosensitivity induction and cell death in yeast Saccharomyces cerevisiae; Influencia da acao oxidante do selenio na inducao da radiossensibilidade e morte celular na levedura Saccharomyces cerevisiae

Energy Technology Data Exchange (ETDEWEB)

Porto, Barbara Abranches de Araujo

2012-07-01

Ionizing radiations are from both natural sources such as from anthropogenic sources. Recently, radiotherapy has emerged as one of the most common therapies against cancer. Co-60 irradiators (cobalt-60 linear accelerators) are used to treat of malignant tumors routinely in hospitals around the world. Exposure to ionizing radiation can induce changes in cellular macromolecules and affect its functions, because they cause radiolysis of the water molecule generating reactive oxygen species, which can cause damage to virtually all organelles and cell components known as oxidative damage that can culminate in oxidative stress. Oxidative stress is a situation in which the balance between oxidants and antioxidants is broken resulting in excessive production of reactive species, it is not accompanied by the increase in antioxidant capacity, making it impossible to neutralize them. Selenium is a micronutrient considered as antioxidant, antiinflammatory, which could prevent cancer. Selenium in biological system exists as seleno proteins. Nowadays, 25 human seleno proteins have been identified, including glutathione peroxidase, an antioxidant enzyme. Yeasts have the ability to incorporate various metals such as iron, cadmium, zinc and selenium, as well as all biological organisms. The yeast Saccharomyces cerevisiae, unlike mammalian cells is devoid of seleno proteins, being considered as a practical model for studies on the toxicity of selenium, without any interference from the metabolism of seleno proteins. Moreover, yeast cells proliferate through the fermentation, the microbial equivalent of aerobic glycolysis in mammals and the process is also used by tumors. Several reports show that the pro-oxidante effects and induced toxic selenium compounds occur at lower doses and in malignant cells compared with benign cells. Therefore selenium giving a great therapeutic potential in cancer treatment .Our objective was to determine whether selenium is capable to sensitize yeasts

A study of eukaryotic response mechanisms to atmospheric pressure cold plasma by using Saccharomyces cerevisiae single gene mutants

International Nuclear Information System (INIS)

Feng Hongqing; Wang Ruixue; Sun Peng; Wu Haiyan; Liu Qi; Li Fangting; Fang Jing; Zhang Jue; Zhu Weidong

2010-01-01

The mechanisms of eukaryotic cell response to cold plasma are studied. A series of single gene mutants of eukaryotic model organism Saccharomyces cerevisiae are used to compare their sensitivity to plasma treatment with the wild type. We examined 12 mutants in the oxidative stress pathway and the cell cycle pathway, in which 8 are found to be hypersensitive to plasma processing. The mutated genes' roles in the two pathways are analyzed to understand the biological response mechanisms of plasma treatment. The results demonstrate that genes from both pathways are needed for the eukaryotic cells to survive the complex plasma treatment.

Fatty acid metabolism in Saccharomyces cerevisiae

NARCIS (Netherlands)

van Roermund, C. W. T.; Waterham, H. R.; IJlst, L.; Wanders, R. J. A.

2003-01-01

Peroxisomes are essential subcellular organelles involved in a variety of metabolic processes. Their importance is underlined by the identification of a large group of inherited diseases in humans in which one or more of the peroxisomal functions are impaired. The yeast Saccharomyces cerevisiae has

EFFECTS OF IMMUNOSTIMULANTS ON BROILERS SUFFERING FROM INFECTIOU: BURSAL DISEASE

Directory of Open Access Journals (Sweden)

F. Mushtaq, S. A. Khan, A. Aslam, K. Saeed1, G. Saleem and H. Mushtaq

2003-01-01

Full Text Available This project was aimed to evaluate immunostimulatory effects of three therapeutic substances in broilers suffering from infectious bursal disease (IBD. For this purpose, 150 chicks were divided into five equal groups i.e. A, B, C, D and E having 30 birds each. Group A, B, C and D were challenged with infectious bursal disease virus. There were three immunostimulatory treatments i.e. levamisole (group A, vitamin E (group B, and bursinex (group C. Groups D and E were untreated control. Bursa body weight index, histopathology of bursa of Fabricius, plasma cell counting in Harderian gland and estimation of antibody response against infectious bursal disease virus was recorded. Vitamin E played a major role in improving the condition of birds suffering from infectious bursal disease, as it showed increased bursa body weight index (BBIx, less histopathological lesions in bursa of Fabricius, increased number of plasma cells in Harderian gland and high antibody response in infectious bursal disease infected broilers as compared to levamisole and bursinex. Levamisole played a minor role in improving condition of birds, while bursinex did not seem to be much effective against infectious bursal disease virus in this study.

[Temporal meaning of suffering].

Science.gov (United States)

Porée, J

2015-09-01

If we had to find a few simple words to express what a suffering human being experiences, no matter what ills are causing the suffering and no matter what circumstances underlie the ills themselves, we could unmistakably say that it is the experience of not being able to go on like this. Suffering can be described, in this same sense, as an alteration in temporality. However, describing suffering as such only makes sense if we already have a conception of normal temporality. Yet for this, philosophical tradition offers not one but four competing conceptions. In the present article, we begin by briefly presenting these different conceptions. We then show how each one sheds light, by way of contrast, on a phenomenon whose meaning thus appears to be essentially negative. But does this phenomenon have a negative meaning only? Doesn't it correspond as much to a transformation as an alteration of temporality? This is what we will strive to establish in the third part of the article by relating suffering to hope, in a paradoxical sense of the term. Of the four conceptions of time likely to shed a contrasting light on the upheavals that suffering introduces into our life experience, the one described by Aristotle in Physics is historically the first. In particular, the notion of succession originates therein. But this conception does not account for what makes time the unit of a past, a present, and a future. In Book XI of Confessions, St. Augustine situated this unit not in nature but in the human mind. Hence, his definition of time as a distension of the soul and the necessary division into physical time and psychic time it entails. Husserl's Lessons on the phenomenology of the consciousness of internal time lend credit to this division, but they illuminate only the internal constitution of the "present", which is at the heart of the psychological conception of time. In Being and Time, Heidegger breaks away from this long-standing tradition; in his view, physical time

Interaction of Saccharomyces boulardii with Salmonella enterica serovar Typhimurium protects mice and modifies T84 cell response to the infection.

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Flaviano S Martins

Full Text Available BACKGROUND: Salmonella pathogenesis engages host cells in two-way biochemical interactions: phagocytosis of bacteria by recruitment of cellular small GTP-binding proteins induced by the bacteria, and by triggering a pro-inflammatory response through activation of MAPKs and nuclear translocation of NF-kappaB. Worldwide interest in the use of functional foods containing probiotic bacteria for health promotion and disease prevention has increased significantly. Saccharomyces boulardii is a non-pathogenic yeast used as a probiotic in infectious diarrhea. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we reported that S. boulardii (Sb protected mice from Salmonella enterica serovar Typhimurium (ST-induced death and prevented bacterial translocation to the liver. At a molecular level, using T84 human colorectal cancer cells, we demonstrate that incubation with Sb before infection totally abolished Salmonella invasion. This correlates with a decrease of activation of Rac1. Sb preserved T84 barrier function and decreased ST-induced IL-8 synthesis. This anti-inflammatory effect was correlated with an inhibitory effect of Sb on ST-induced activation of the MAPKs ERK1/2, p38 and JNK as well as on activation of NF-kappaB. Electron and confocal microscopy experiments showed an adhesion of bacteria to yeast cells, which could represent one of the mechanisms by which Sb exerts its protective effects. CONCLUSIONS: Sb shows modulating effects on permeability, inflammation, and signal transduction pathway in T84 cells infected by ST and an in vivo protective effect against ST infection. The present results also demonstrate that Sb modifies invasive properties of Salmonella.

Interaction of Saccharomyces boulardii with Salmonella enterica Serovar Typhimurium Protects Mice and Modifies T84 Cell Response to the Infection

Science.gov (United States)

Martins, Flaviano S.; Dalmasso, Guillaume; Arantes, Rosa M. E.; Doye, Anne; Lemichez, Emmanuel; Lagadec, Patricia; Imbert, Veronique; Peyron, Jean-François; Rampal, Patrick; Nicoli, Jacques R.; Czerucka, Dorota

2010-01-01

Background Salmonella pathogenesis engages host cells in two-way biochemical interactions: phagocytosis of bacteria by recruitment of cellular small GTP-binding proteins induced by the bacteria, and by triggering a pro-inflammatory response through activation of MAPKs and nuclear translocation of NF-κB. Worldwide interest in the use of functional foods containing probiotic bacteria for health promotion and disease prevention has increased significantly. Saccharomyces boulardii is a non-pathogenic yeast used as a probiotic in infectious diarrhea. Methodology/Principal Findings In this study, we reported that S. boulardii (Sb) protected mice from Salmonella enterica serovar Typhimurium (ST)-induced death and prevented bacterial translocation to the liver. At a molecular level, using T84 human colorectal cancer cells, we demonstrate that incubation with Sb before infection totally abolished Salmonella invasion. This correlates with a decrease of activation of Rac1. Sb preserved T84 barrier function and decreased ST-induced IL-8 synthesis. This anti-inflammatory effect was correlated with an inhibitory effect of Sb on ST-induced activation of the MAPKs ERK1/2, p38 and JNK as well as on activation of NF-κB. Electron and confocal microscopy experiments showed an adhesion of bacteria to yeast cells, which could represent one of the mechanisms by which Sb exerts its protective effects. Conclusions Sb shows modulating effects on permeability, inflammation, and signal transduction pathway in T84 cells infected by ST and an in vivo protective effect against ST infection. The present results also demonstrate that Sb modifies invasive properties of Salmonella. PMID:20111723

Cell adsorption and selective desorption for separation of microbial cells by using chitosan-immobilized silica.

Science.gov (United States)

Kubota, Munehiro; Matsui, Masayoshi; Chiku, Hiroyuki; Kasashima, Nobuyuki; Shimojoh, Manabu; Sakaguchi, Kengo

2005-12-01

Cell adsorption and selective desorption for separation of microbial cells were conducted by using chitosan-immobilized silica (CIS). When chitosan was immobilized onto silica surfaces with glutaraldehyde, bacterial cells adsorbed well and retained viability. Testing of the adsorption and desorption ability of CIS using various microbes such as Escherichia coli, Aeromonas hydrophila, Pseudomonas aeruginosa, Bacillus subtilis, Micrococcus luteus, Staphylococcus aureus, Staphylococcus epidermidis, Lactobacillus casei, Streptococcus mutans, Streptococcus sobrinus, Streptococcus salivarius, Saccharomyces cerevisiae, Saccharomyces ludwigii, and Schizosaccharomyces pombe revealed that most microbes could be adsorbed and selectively desorbed under different conditions. In particular, recovery was improved when L-cysteine was added. A mixture of two bacterial strains adsorbed onto CIS could also be successfully separated by use of specific solutions for each strain. Most of the desorbed cells were alive. Thus, quantitative and selective fractionation of cells is readily achievable by employing chitosan, a known antibacterial material.

The sequence spectrum of frameshift reversions obtained with a novel adaptive mutation assay in Saccharomyces cerevisiae

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Erich Heidenreich

2016-12-01

Full Text Available Research on the mechanisms of adaptive mutagenesis in resting, i.e. non-replicating cells relies on appropriate mutation assays. Here we provide a novel procedure for the detection of frameshift-reverting mutations in yeast. Proliferation of non-reverted cells in this assay is suppressed by the lack of a fermentable carbon source. The test allele was constructed in a way that the reversions mimic microsatellite instability, a condition often found in cancer cells. We show the cell numbers during these starvation conditions and provide a DNA sequence spectrum of a representative set of revertants. The data in this article support the publication "Glucose starvation as a selective tool for the study of adaptive mutations in Saccharomyces cerevisiae" (Heidenreich and Steinboeck, 2016 [1].

Benefit of brain prophylactic irradiation in patients suffering from a small-cell bronchial cancer: retrospective study on 289 cases

International Nuclear Information System (INIS)

Assouline, A.; Tai, P.; Jancewicz, M.; Joseph, K.; Krzisch, C.; Yu, E.

2011-01-01

The authors report a study which aimed at determining the benefit of a brain prophylactic irradiation for patients suffering from a localized small-cell bronchial cancer and in partial response to the local-regional treatment of their disease. A retrospective analysis has been performed on a set of 289 patients who had been treated by chemo-radiotherapy with or without brain prophylactic irradiation between 1981 and 2007. Data are discussed in terms of remission level, survival with respect to the level of response to the local-regional treatment. Depending on this response level the irradiation increases or not the probability of global survival, or the probability of specific survival. Short communication

Crystallization and X-ray diffraction analysis of dihydropyrimidinase from Saccharomyces kluyveri

International Nuclear Information System (INIS)

Dobritzsch, Doreen; Andersen, Birgit; Piškur, Jure

2005-01-01

Dihydropyrimidinase from the yeast S. kluyveri was crystallized by vapour diffusion. The crystals belong to space group P2 1 (unit-cell parameters a = 91.0, b = 73.0, c = 161.4 Å, β = 91.4°) and diffracted to 2.6 Å resolution. Dihydropyrimidinase (EC 3.5.2.2) catalyzes the second step in the reductive pathway of pyrimidine degradation, the hydrolysis of 5,6-dihydrouracil and 5,6-dihydrothymine to the corresponding N-carbamylated β-amino acids. Crystals of the recombinant enzyme from the yeast Saccharomyces kluyveri diffracting to 2.6 Å at a synchrotron-radiation source have been obtained by the hanging-drop vapour-diffusion method. They belong to space group P2 1 (unit-cell parameters a = 91.0, b = 73.0, c = 161.4 Å, β = 91.4°), with one homotetramer per asymmetric unit

Functional screening of aldehyde decarbonylases for long-chain alkane production by Saccharomyces cerevisiae

DEFF Research Database (Denmark)

Kang, Min-Kyoung; Zhou, Yongjin J.; Buijs, Nicolaas A.

2017-01-01

Background: Low catalytic activities of pathway enzymes are often a limitation when using microbial based chemical production. Recent studies indicated that the enzyme activity of aldehyde decarbonylase (AD) is a critical bottleneck for alkane biosynthesis in Saccharomyces cerevisiae. We therefore...... detected in other AD expressed yeast strains. Dynamic expression of SeADO and CwADO under GAL promoters increased alkane production to 0.20 mg/L/OD600 and no fatty alcohols, with even number chain lengths from C8 to C14, were detected in the cells. Conclusions: We demonstrated in vivo enzyme activities...

Oxygen requirements for formation and activity of the squalene expoxidase in Saccharomyces cerevisiae

Science.gov (United States)

Jahnke, L.; Klein, H. P.

1983-01-01

The effect of oxygen on squalene epoxidase activity in Saccharomyces cerevisiae was investigated. In cells grown in standing cultures, the epoxidase was localized mainly in the 'mitochondrial' fraction. Upon aeration, enzyme activity increased and the newly formed enzyme was associated with the 'microsomal' fraction. At 0.03 percent (vol/vol) oxygen, epoxidase levels doubled, whereas the ergosterol level was only slightly increased. Cycloheximide inhibited the increase in epoxidase under these conditions. An apparent K sub m for oxygen of 0.38 percent (vol/vol) was determined from a crude particulate preparation for the epoxidase.

Damage-induced ectopic recombination in the yeast Saccharomyces cerevisiae.

Science.gov (United States)

Kupiec, M; Steinlauf, R

1997-06-09

Mitotic recombination in the yeast Saccharomyces cerevisiae is induced when cells are irradiated with UV or X-rays, reflecting the efficient repair of damage by recombinational repair mechanisms. We have used multiply marked haploid strains that allow the simultaneous detection of several types of ectopic recombination events. We show that inter-chromosomal ectopic conversion of lys2 heteroalleles and, to a lesser extent, direct repeat recombination (DRR) between non-tandem repeats, are increased by DNA-damaging agents; in contrast, ectopic recombination of the naturally occurring Ty element is not induced. We have tested several hypotheses that could explain the preferential lack of induction of Ty recombination by DNA-damaging agents. We have found that the lack of induction cannot be explained by a cell cycle control or by an effect of the mating-type genes. We also found no role for the flanking long terminal repeats (LTRs) of the Ty in preventing the induction. Ectopic conversion, DRR, and forward mutation of artificial repeats show different kinetics of induction at various positions of the cell cycle, reflecting different mechanisms of recombination. We discuss the mechanistic and evolutionary aspects of these results.

Mating-Type Genes and MAT Switching in Saccharomyces cerevisiae

Science.gov (United States)

Haber, James E.

2012-01-01

Mating type in Saccharomyces cerevisiae is determined by two nonhomologous alleles, MATa and MATα. These sequences encode regulators of the two different haploid mating types and of the diploids formed by their conjugation. Analysis of the MATa1, MATα1, and MATα2 alleles provided one of the earliest models of cell-type specification by transcriptional activators and repressors. Remarkably, homothallic yeast cells can switch their mating type as often as every generation by a highly choreographed, site-specific homologous recombination event that replaces one MAT allele with different DNA sequences encoding the opposite MAT allele. This replacement process involves the participation of two intact but unexpressed copies of mating-type information at the heterochromatic loci, HMLα and HMRa, which are located at opposite ends of the same chromosome-encoding MAT. The study of MAT switching has yielded important insights into the control of cell lineage, the silencing of gene expression, the formation of heterochromatin, and the regulation of accessibility of the donor sequences. Real-time analysis of MAT switching has provided the most detailed description of the molecular events that occur during the homologous recombinational repair of a programmed double-strand chromosome break. PMID:22555442

Co-cultivation of non-conventional yeast with Saccharomyces cerevisiae to increase the aroma complexity of fermented beverages

NARCIS (Netherlands)

Rijswijck, van Irma M.H.

2017-01-01

Yeast are used as workhorses to convert hopped wort into beer. Conventionally, such yeasts belong to the genus Saccharomyces and most research on fermentation of wort for the production of beer has focussed on the species Saccharomyces cerevisiae and Saccharomyces