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Sample records for cerevisiae em caldo

  1. ACÚMULO DE CÁDMIO POR Saccharomyces cerevisiae EM CALDO DE CANA-DE-AÇÚCAR CONTAMINADO COM ACETATO DE CÁDMIO

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    Mariano-da-Silva Samuel

    1999-01-01

    Full Text Available O presente trabalho visou estudar o acúmulo de cádmio (Cd por Saccharomyces cerevisiae, fermentando mosto de caldo de cana-de-açúcar com contaminações controladas, em níveis sub-tóxicos do citado metal. As condições de fermentação foram similares às reinantes na produção industrial de etanol. O mosto, não esterelizado, continha 12% de açúcares redutores totais (ART e pH 4,5. Para a contaminação controlada empregou-se acetato de cádmio em quatro níveis de contaminações (0,5; 1,0; 2,0 e 5,0 mg Cd kg-1 mosto. A inoculação do mosto foi executada com fermento de panificação (10% p/p. Após a fermentação (4 horas foram determinados, porcentagem de fermento no vinho centrifugado e teor alcoólico do mesmo. Na levedura separada foram determinados peso úmido, matéria seca, proteína bruta e teores de cádmio por espectrofotometria de absorção atômica. Em todos os níveis de contaminação estudados houve acúmulo de Cd pela levedura.

  2. ACÚMULO DE CÁDMIO POR Saccharomyces cerevisiae FERMENTANDO MOSTO DE CALDO DE CANA ACCUMULATION OF CADMIUM BY Saccharomyces cerevisiae FERMENTING MUST OF SUGAR-CANE

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    S.M.G. da SILVA

    1998-10-01

    Full Text Available O presente trabalho estudou o acúmulo de cádmio (Cd por Saccharomyces cerevisiae, fermentando mosto de caldo de cana com contaminações controladas, em níveis sub-tóxicos, do citado metal. O ensaio de fermentação foi conduzido em erlenmayers de 500 mL, acondicionados em estufa B.O.D. O mosto, não esterilizado, continha 12% de açúcares redutores totais (ART e pH 4,5. Para a contaminação controlada empregou-se cloreto de cádmio em quatro níveis de contaminações: 0,5; 1,0; 2,0 e 5,0 mg Cd kg-1 mosto. A inoculação do mosto foi executada com fermento de panificação (10% p/p. Após a fermentação (4 horas foram determinados, porcentagem de fermento no vinho centrifugado e teor alcoólico do mesmo. Na levedura separada por centrifugação, foram determinados peso úmido, matéria seca, proteína bruta e teores de cádmio por espectrofotometria de absorção atômica. Em todos os níveis de contaminação estudados houve acúmulo de Cd pela levedura.The aim of this paper is to study the absorption and cadmium (Cd concentration by Saccharomyces cerevisiae, fermenting must of sugar-cane, with control contamination, under toxic levels of cadmium (mg Cd kg-1 must. The fermentation was performed in 500 mL erlemmayers. Non-sterilized must showed 12% of total reducing sugar (w/w e pH 4,5. For the control contamination, was applied cadmium chloride, with four levels of contamination: 0,5; 1,0; 2,0 and 5,0 mg Cd kg-1 must. The inoculation of must was carried out with bread yeast (10% w/w. After fermentation (4 hours, samples were colected to evaluate cellular viability and yeast percentage. Fermenting mid was centrifuged and analysis of mid without yeast and raw yeast were performed. The alcohol content was measured , as well as the total humid weight for the yeast material, raw protein and heavy metal by atomic absorption spectroscopy. Watch all level studied have accumulation of cadmium at yeast.

  3. Minerais em melados e em caldos de cana Minerals in sugar cane syrup and cane juice

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    Fernanda dos Santos Nogueira

    2009-12-01

    Full Text Available A cana-de-açúcar está entre as culturas que apresenta larga escala de adaptações às condições climáticas, sendo utilizada para a fabricação de diversos produtos. Dentre os produtos derivados da cana-de-açúcar, o melado é tido popularmente como um alimento rico em ferro. Este trabalho objetivou conhecer a concentração de alguns minerais em melados comerciais e em melados preparados com equipamentos de aço inoxidável. Ao todo foram 20 amostras, 10 de cada tipo. As amostras foram preparadas para análise por oxidação da matéria orgânica por via úmida e os teores de Ca, Mg, Cu, Mn, Zn e Fe foram determinados por espectroscopia de absorção atômica, Na e K por fotometria de chama e P por colorimetria. Concluiu-se, com este trabalho, que os teores médios dos minerais Fe, P, Na e Mg foram significativamente mais elevados nos melados comerciais do que nos melados feitos com equipamentos inox. O contrário foi encontrado para o mineral cálcio, que apresentou teor mais elevado nos melados feitos no laboratório, mas condizentes com os teores encontrados nos caldos de cana. Não houve diferença significativa nos teores dos demais minerais.Sugar cane is an easily adaptable crop to diverse climate conditions, and it is used in the manufacturing of many different products. Among those products is the syrup, which is popularly known to be good sources of iron. In this work, we aimed to measure the concentration of some minerals in commercial sugar cane syrup brands and syrup prepared in the laboratory using stainless steel equipment. A total of 20 samples were analyzed, 10 of commercial brands and ten prepared in the laboratory. The samples were prepared by wet-air oxidation of organic matter and the contents of Ca, Mg, Cu, Mn, Zn, and Fe were determined by atomic absorption. Na and K were determined by photometry and P by colorimetry. It was found that the mean concentration of Fe, P, Na, and Mn were higher in the commercial

  4. Viabilidade celular de Saccharomyces cerevisiae em cultura mista com Lactobacillus fermentum

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    OLIVEIRA-FREGUGLIA R. M.

    1998-01-01

    Full Text Available O presente trabalho teve por objetivo avaliar os efeitos de L. fermentum em cultura mista com S. cerevisiae sobre a viabilidade celular da levedura, bem como outros parâmetros relacionados com os produtos metabólicos bacterianos. Os microrganismos foram cultivados individualmente em meio de caldo de cana-de-açúcar diluído e suplementado com extrato de levedura e peptona. A partir da mistura de ambas as culturas foi acompanhada a viabilidade celular da levedura em ensaios denominados: cultura mista ativa, bactéria inativada por esterilização e inativada por agentes antimicrobianos. Nos cultivos onde foi observada floculação, foi testada a ação de enzimas do grupo peptidohidrolases (papaína, bromelina e ficina. A cultura mista ativa apresentou redução da viabilidade levedura de 96% em 12 horas. Nos ensaios utilizando as culturas bacterianas inativadas, as reduções médias foram de 50 a 60% nas primeiras 12 horas, chegando a 80-90% com 24 horas. O cultivo bacteriano inativado por esterilização produziu menor redução de viabilidade que os cultivos inativados por agentes antimicrobianos. No experimento com enzimas, foi observada ação desfloculante ainda não relatadas, confirmando a natureza protéica do causal da floculação.

  5. EFEITO DE ONDAS ULTRA-SÔNICAS SOBRE A POPULAÇÃO DE Leuconostoc mesenteroides EM CALDO DE CANA-DE-AÇÚCAR THE EFFECT OF ULTRASOUND WAVES ON THE Leuconostoc mesenteroides POPULATION IN SUGARCANE JUICE

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    Manoel Soares Soares Júnior

    2007-09-01

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    No presente trabalho, irradiou-se caldo de cana-de-açúcar de primeira extração, com ondas ultra-sônicas, com o objetivo de controlar a bactéria <em>Leuconostoc mesenteroidesem>. Foi aplicada a metodologia de superfície de resposta (modelo central composto, para avaliar o efeito dos tratamentos. A variável resposta avaliada foi taxa de mortalidade (TM% da população de <em>L. mesenteroidesem>. Os resultados mostraram que a maior taxa de mortalidade, 10,55%, foi obtida com a potência de 50 W, por 225 segundos, em caldo de cana com 18° Brix, pH 4,5 e 45°C.

    PALAVRAS-CHAVE: Indústria açucareira; cana-de-açúcar; ultra-som.

    In the present work, first extraction sugarcane juice was irradiated with ultrasound waves to control <em>Leuconostoc mesenteroidesem>. Surface response methodology (central composite model was used to evaluate the treatment effects. The response variable was the death rate (DR% of the <em>L. mesenteroidesem> population. The results showed that the highest rate of mortality, 10.55%, was obtained with a power of 50 W for 225 seconds, in sugarcane juice with 18° Brix, pH 4.5 and 45°C.

    KEY-WORDS: Sugar industry; sugarcane; ultrasound.

  6. Avaliação da solubilidade de cobre e zinco em caldos de leguminosas Evaluation of the solubility of copper and zinc in a salty, watrry vegetatable soup

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    Édira Castello Branco de Andrade

    2003-12-01

    Full Text Available Os metais cobre e zinco podem se apresentar sob diversas formas químicas na natureza: como sais, estando sob a forma de íons I e II ou como compostos orgânicos, complexados com aminoácidos e proteínas. A forma mais biodisponível ao organismo é a forma de compostos organo quelados. Avaliando os teores dos metais em caldo de leguminosas processadas termicamente em meios salino e aquoso é possível avaliar a solubilidade destes metais. Duas marcas e dois lotes de amostras de feijão preto, feijão branco, feijão carioquinha, feijão mulatinho, feijão manteiga, ervilha e lentilha foram processadas termicamente em meios salino e aquoso e determinou-se os teores totais de cobre e zinco em seus caldos. Os caldos foram dissolvidos em HCl 2molL-1 e o teor total de cobre e zinco nas amostras foi determinado através da espectroscopia de absorção atômica em chama. Na análise da rejeição de resultados foi aplicado o teste Dixon e o teste t de student. Os resultados mostraram que a solubilidade média dos metais cobre e zinco nos meios aquoso e salino foram respectivamente 8 e 6%. Acredita-se que os compostos de cobre e zinco nas leguminosas analisadas não são compostos inorgânicos facilmente solúveis em água. Estudos de especiação podem auxiliar na análise da biodisponibilidade destes metais.Copper and zinc can appear in nature under chemical forms, such as salts, being as íons I and II or as organic compounds, synthesized as amino acids and proteins. The most bio-available form to the human body are organic compounds. The solubility of these metals can be determined by evaluating their ratio in a both of legumes thermally processed in an aqueous and a saline mediium. Samples of several varieties of beans, peas, lentils and chickpeas, in two batches containing two different brands of each variety, were thermally processeced in an aqueous and a saline medium and the total ratio of copper and zinc in their respective broths was

  7. PERCEPÇÃO DOS CONSUMIDORES SOBRE O COMÉRCIO DE ALIMENTOS DE RUA E AVALIAÇÃO DO TESTE DE MERCADO DO CALDO DE CANA PROCESSADO E EMBALADO EM SEIS MUNICÍPIOS DO ESTADO DE SÃO PAULO, BRASIL

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    A. C. G. OLIVEIRA

    2008-11-01

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    O caldo de cana é uma bebida popularmente consumida e muito apreciada no Brasil. O presente trabalho teve como objetivos descrever os hábitos e as preferências alimentares, o conhecimento sobre condições higiênico-sanitárias e doenças veiculadas por alimentos, a opinião sobre os pontos de venda de caldo de cana, a aceitação comercial e a disponibilidade de pagar valores adicionais pelo caldo de cana processado e embalado, aplicando-se 350 questionários em seis municípios paulistas. Dentre os entrevistados, (51% consideram seu hábito alimentar saudável; (59% interessam-se pela segurança de sua alimentação e (63% apresentam receio em se alimentar em comércio de alimentos de rua. Dentre os alimentos consumidos rotineiramente pelos entrevistados, os lanches foram os mais citados. Entre os entrevistados, 80% mencionaram apreciar caldo de cana e sua preferência pela forma de consumo foi com adição de suco de limão. Cerca de 55% dos entrevistados mencionaram que consumiriam a bebida processada e embalada, com maior freqüência e a disponibilidade média de pagar valores adicionais foi de R$ 0,54, evidenciando que o produto teria boa aceitação comercial.

  8. CLSI broth microdilution method for testing susceptibility of Malasseziapachydermatis to thiabendazole CLSI método de Microdiluição em Caldo para teste de suscetibilidade da Malassezia pachydermatis frente ao tiabendazol

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    Patrícia da Silva Nascente

    2009-06-01

    Full Text Available Thiabendazole, classified as antiparasitic and also used as an antifungal drug, can be found as otological solution indicated for treatment of parasitic and fungal external otitis in small animals. Malassezia pachydermatis is a yeast recognized as a normal inhabitant on the skin and mucous membranes of dogs and cats. However, it is considered an opportunistic agent that causes external otitis and dermatitis in these animals. The aim of this study was to evaluate the in vitro effect of thiabendazole against 51 isolates of M. pachydermatis using the CLSI Broth Microdilution method that has been adapted for this yeast species (NCCLS, 2002. Based on this test, the Minimum Inhibitory Concentrations (MIC of thiabendazol was calculated. Subsequently, the susceptibility of each isolate against this antifungal was determined. It was observed that the MIC of thiabendazole against M. pachydermatis ranged from 0.03 to > 4 μg/mL. A total of 13.7% of the isolates were found to be resistant, 47.1% were intermediate and 39.2% were sensitive to the drug. The rate of resistance of the yeasts against thiabendazole was similar to the results previously obtained with other antifungals, while the adapted broth microdilution technique used in this study proved to be efficient.Tiabendazol, um fármaco classificado como antiparasitário e também usado como antifúngico, pode ser encontrado como solução otologica indicada no tratamento da otite externa parasitária e fungica em pequenos animais. Malassezia pachydermatis é uma levedura considerada habitante normal da pele e das mucosas de cães e gatos. Entretanto, considera-se um agente do oportunista causador de otite externa e dermatite nestes animais. A finalidade deste estudo foi avaliar o efeito in vitro do tiabendazol frente a 51 amostras de M. pachydermatis através do método CLSI de Microdiluição em Caldo adaptado para esta espécie de levedura (NCCLS, 2002. Baseado neste teste calculou-se as Concentra

  9. Encapsulation-Induced Stress Helps <em>Saccharomyces cerevisiae em>Resist Convertible Lignocellulose Derived Inhibitors

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    Johan O. Westman

    2012-09-01

    Full Text Available The ability of macroencapsulated <em>Saccharomyces cerevisiae em>CBS8066<em> em>to withstand readily and not readily <em>in situem> convertible lignocellulose-derived inhibitors was investigated in anaerobic batch cultivations. It was shown that encapsulation increased the tolerance against readily convertible furan aldehyde inhibitors and to dilute acid spruce hydrolysate, but not to organic acid inhibitors that cannot be metabolized anaerobically. Gene expression analysis showed that the protective effect arising from the encapsulation is evident also on the transcriptome level, as the expression of the stress-related genes <em>YAP1em>, <em>ATR1em> and <em>FLR1em> was induced upon encapsulation. The transcript levels were increased due to encapsulation already in the medium without added inhibitors, indicating that the cells sensed low stress level arising from the encapsulation itself. We present a model, where the stress response is induced by nutrient limitation, that this helps the cells to cope with the increased stress added by a toxic medium, and that superficial cells in the capsules degrade convertible inhibitors, alleviating the inhibition for the cells deeper in the capsule.

  10. In vitro effect of intracanal medicaments on strict anaerobes by means of the broth dilution method Efeito in vitro de medicações intracanal sobre anaeróbios estritos pelo método de diluição em caldo

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    Odila Pereira da Silva ROSA

    2002-03-01

    Full Text Available The determination of bacterial susceptibility to intracanal medicaments is a necessity. Nevertheless, few studies utilize the proper methodology to carry out that evaluation with anaerobes. In this study, the steps of a broth dilution method, carried out in microplates (microdilution and tubes (macrodilution, to test the effect of traditional intracanal medicaments on anaerobic bacteria are described. The results are presented as values of minimal inhibitory and bactericidal concentrations (MIC and MBC. Standardized inocula of the anaerobic bacteria Prevotella nigrescens (ATCC 33563, Fusobacterium nucleatum (ATCC 25586 and Clostridium perfringens (ATCC 13124, in reinforced Clostridium medium (RCM and supplemented Brucella broth, were submitted to different concentrations of calcium hydroxide, chlorhexidine digluconate, camphorated paramonochlorophenol and formocresol solutions. The drugs were diluted in the same culture broths, in microplates and tubes, and were then incubated in anaerobiosis jars at 37ºC for 48 or 96 hours. The determination of MICs was carried out through visual and spectrophotometric readings, and the determination of MBCs, through the plating of aliquots on RCM-blood agar. For that kind of study, the macromethod with spectrophotometric reading should be the natural choice. MICs and MBCs obtained with the macromethod were compatible with the known clinical performance of the studied medications, and the values varied according to the bacteria and culture media employed. RCM was the most effective medium and C. perfringens, the most resistant microorganism.A determinação da suscetibilidade bacteriana aos medicamentos intracanal é uma necessidade, mas são poucos os estudos que utilizam metodologia própria para anaeróbios estritos nessa avaliação. Neste estudo, são descritos os passos de um método de diluição em caldo, feito em microplacas (microdiluição e em tubo (macrodiluição, para testar a ação de

  11. EFFICIENCY OF DOUBLE STEPS ENRICHMENT IN THE UVM AND FRASER BROTHES AND PERFORMANCE OF LPM AND LSAB-CAN AGARS TO DETECTION OF Listeria spp. IN NATURALLY CONTAMINATED CHICKEN MEAT EFICIÊNCIA DO ENRIQUECIMENTO EM DUPLO ESTÁGIO REALIZADO NOS CALDOS UVM E FRASER E DESEMPENHO DOS ÁGARES LPM E LSAB-CAN PARA A DETECÇÃO DE Listeria spp. EM CARNE DE FRANGO NATURALMENTE CONTAMINADA

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    Iolanda Aparecida Nunes

    2007-09-01

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    It was determined the performance of two selective broths and two agars to isolate <em>Listeria> from chicken meat naturally contaminated, acquired in the supermarkets of Goiânia-Goiás, between January and June 1992. Methodology of isolation involved the utilization of two-stage selective enrichment in the University of Vermont and Fraser broths and plating in lithium chloride-phenyletanol-moxalactam agar and the <em>Listeria> selective agar base supplemented with cicloheximide, acriflavine and nalidixic acid. Incubation was done at 300C for 48 hours. Cultures of secondary enrichment broth were inoculated in duplicated plates with and without previous treatment with a 0.25% potassium hydroxide solution during one minute, while the plates from primary enrichment broth were inoculated only with treated cultures. Primary and secondary selective broths showed comparable efficiency at the statistic point of view (Z= -1.7393<1.96, identifying 90.28% and 97.22% of all positive samples of this experiment, respectively. Using the lithium chloride-pheniletanol-moxalactam agar and the <em>Listeria> selective agar base supplemented with cicloheximide, acriflavine and nalidixic acid were detected 98.61% and 54.17% of the positive samples. These differences were significant at statistic view. The treatment of broths with 0.25% potassium hydroxide showed a little reduction in the number of positive samples detected.

    KEY-WORDS: <em>Listeria>; enrichment broth; chicken meat.

    No presente trabalho, avaliou-se o desempenho de dois caldos e dois ágares seletivos para o isolamento de <em>Listeria> a partir de carne de frango naturalmente contaminada, adquirida no comércio varejista de Goiânia - GO, no período de janeiro a junho de 1992. A metodologia de isolamento e

  12. DETERMINAÇÃO RÁPIDA E AUTOMÁTICA DE AÇÚCARES REDUTORES EM CALDO DE CANA-DE-AÇÚCAR

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    Fabio Benincasa

    2012-01-01

    Os monossacarídeos (glicose e frutose) presentes na cana-de-açúcar são açúcares redutores por possuírem grupo carbonílico livres, capazes de se oxidarem na presença de agentes oxidantes. Os métodos analíticos clássicos (Lane-Eynon, Benedict, complexométrica-EDTA, Luff-Schoorl, Musson-Walker, Somogyi-Nelson) baseiam-se na redução de íons cobre em soluções alcalinas. Algumas indústrias sucroalcooleiras utilizam a metodologia de Lane-Eynon, outras o aparelho REDUTEC e outras realizam o calculo d...

  13. EFFICIENCY OF THE ENRICHMENT BROTHES (LEB1 AND LEB2 AND SELECTIVE AGARS (LPM AND LSAB-CAN TO ISOLATE BACTERIA OF THE GENUS Listeria IN MEAT AND RESIDUAL WATER OF WASHING CARCASS EFICIÊNCIA DOS CALDOS DE ENRIQUECIMENTO (LEB1 E LEB2 E DOS ÁGARES SELETIVOS (LPM E LSAB-CAN NO ISOLAMENTO DE BACTÉRIAS DO GÊNERO Listeria EM CARNE BOVINA E ÁGUA RESIDUÁRIA DE LAVAGEM DE CARCAÇA

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    Albenones José de Mesquita

    2007-09-01

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    In this paper it was observed the efficiency of enrichment brothes for <em>Listeria> (LEB1 and LEB2, associated to the passage of the culture through a 0.25% potassium hidroxide solution, verifying that the secondary enrichment broth (LEB2 and LEB2KOH was better than the primary enrichment broth (LEB1KOH for this purpose. On the other hand, lithium chloride-phenylethanol-moxalactam agar and the selective <em>Listeria> agar base, supplemented with cicloheximide, acriflavine and nalidixic acid (LSAIB-CAN showed equivalency, at the statistic point of view (p=0.l442, in relation to the number of positive samples for <em>Listeria> spp., although the LSAB-CAN agar had given the greatest number of bacteria isolated from this genus.

    KEY-WORDS: <em>Listeria>; enrichment broth; selective agar.

    No presente trabalho verificou-se a eficiência dos caldos de enriquecimento para <em>Listeria> (LEB1 e LEB 2 associados à passagem da cultura por uma solução de hidróxido de potássio a 0,25%, constatando-se que o caldo de enriquecimento secundário (LEB2 e LEB2KOH foi superior ao caldo de enriquecimento primário (LEB1KOH. Por outro lado, o ágar cloreto de lítio-feniletanol-moxalactam (LPM e o ágar base seletivo para <em>Listeria>, suplementado com cicloheximida, acriflavina e ácido nalidíxico (LSAB-CAN equivaleram-se estatisticamente (p= 0,l442 em relação ao número de amostras positivas para <em>Listeria>, embora o ágar LSAB-CAN tenha proporcionado um maior número de isolamentos da bactéria.

    PALAVRAS-CHAVE: Caldo de enriquecimento; ágar seletivo; <em>Listeria>.

  14. Effect of the presence of initial ethanol on ethanol production in sugar cane juice fermented by Zymomonas mobilis Efeito da presença de etanol inicial na produção de etanol em caldo de cana-de-açúcar fermentado por Zymomonas mobilis

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    Marcia Sadae Tano

    2003-07-01

    Full Text Available Ethanol production in sugar cane juice in high initial sugar concentration, fermented by Z. mobilis in the presence and absence of ethanol, was evaluated. Ethanol production was low in both media. The presence of initial ethanol in the sugar cane juice reduced ethanol production by 48.8%, biomass production by 25.0% and the total sugar consumption by 28.3%. The presence of initial ethanol in the medium did not affect significantly levan production and biomass yield coefficient (g biomass/g sugar consumed.Foi avaliada a produção de etanol em caldo de cana-de-açúcar com alta concentração de açúcar inicial, fermentado por Z. mobilis, na presença e na ausência de etanol inicial. A produção de etanol nos dois meios foi baixa. A presença de etanol inicial no caldo de cana-de-açúcar causou uma redução de 48,8% na produção de etanol, de 25% na produção de biomassa e de 28,3% no consumo de açúcar total. A presença de etanol inicial ao meio não teve efeito significante para a produção de levana e no coeficiente de produtividade em biomassa (g biomassa/g açúcar consumido.

  15. Estudo comparativo entre as técnicas de diluição em caldo e diluição em ágar, nos antibiogramas para Candida: a comparative study Broth dilution and agar dilution methods applied to Candida sensitivity tests

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    Sydney Hartz Alves

    1992-06-01

    Full Text Available Os autores compararam o desempenho das técnicas de diluição em caldo e diluição em ágar, mediante a determinação da CIM (concentração inibitória mínima e da CFM (concentração fungicida mínima de antifúngicos poliênicos e imidazólicos, frente a diversas espécies de Candida. A concordância entre as técnicas foi variável em função do antifúngico utilizado. Os melhores percentuais de concordância ocorreram quando se realizou o teste com poliênicos. Os autores discutem aspectos que envolvem a problemática dos testes de sensibilidade de leveduras a antifúngicosThe performance of broth dilution method and agar dilution method were compared by MIC (minimal inhibitory concentration and MFC (minimal fungicidal concentration from Candida strains to polyene and imizadole anti-fungal agents. The concordance between these methods was drug dependent. The best percent of concordance were showed when the polyenes were tested. The problems of sensitivity test for yeasts to antifungal drugs are discussed

  16. Dermatophyte susceptibilities to antifungal azole agents tested in vitro by broth macro and microdilution methods Suscetibilidade in vitro de dermatófitos a azóis pelos métodos macro e microdiluição em caldo

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    Emerson Roberto Siqueira

    2008-02-01

    Full Text Available The in vitro susceptibility of dermatophytes to the azole antifungals itraconazole, fluconazole and ketoconazole was evaluated by broth macro and microdilution methods, according to recommendations of the CLSI, with some adaptations. Twenty nail and skin clinical isolates, four of Trichophyton mentagrophytes and 16 of T. rubrum were selected for the tests. Itraconazole minimal inhibitory concentrations (MIC varied from Foi avaliada a suscetibilidade in vitro de dermatófitos aos antifúngicos itraconazol, fluconazol e cetoconazol, pelos métodos macro e microdiluição em caldo, de acordo com as recomendações do CLSI, com algumas modificações. Foram estudados 20 isolados clínicos de lesões de unha e pele, sendo quatro Trichophyton mentagrophytes e 16 T. rubrum. A concentração inibitória mínima (CIM para itraconazol variou de < 0,03 a 0,25 µg/mL pelo método da macrodiluição, e de < 0,03 a 0,5 µg/mL pela microdiluição em caldo; de 0,5 a 64 µg/mL e de 0,125 a 16 µg/mL para fluconazol, respectivamente, pela macro e microdiluição; e de < 0,03 a 0,5 µg/mL por ambos os métodos para cetoconazol. A concordância entre os dois métodos (considerando ± uma diluição foi de 70% para itraconazol, 45% para fluconazol e 85% para cetoconazol. Conclui-se que os isolados estudados foram inibidos por concentrações relativamente baixas dos antifúngicos testados, e os dois métodos apresentam boa concordância, especialmente para itraconazol e cetoconazol.

  17. PREPARAÇÕES DE Saccharomyces cerevisiae ELICITORAS DE FITOALEXINAS EM MESOCÓTILOS DE SORGO

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    N.A. WULFF

    1998-01-01

    Full Text Available A levedura Saccharomyces cerevisiae estimula o acúmulo de fitoalexinas e tem potencial para ser utilizada como agente de controle alternativo no tratamento de doenças fúngicas em sorgo. São descritos aqui os procedimentos iniciais para a purificação de elicitores de fitoalexinas em sorgo, os quais são extraídos das células da levedura S. cerevisiae por autoclavagem, indicando serem termoestáveis. Após precipitacão com etanol, em concentrações finais de 50 e 80%, as moléculas elicitoras permanecem em solução. O acúmulo de fitoalexinas nos mesocótilos é mais elevado quanto maiores os teores de proteínas das amostras elicitoras.The yeast Saccharomyces cerevisiae stimulates phytoalexin accumulation and is a potential agent for biological control of fungal diseases in sorghum. The present investigation establishes the initial steps to purify elicitor molecules of phytoalexins in sorghum from S. cerevisiae. These molecules are extracted using heat and remain in solution after ethanol precipitation. They are active even after autoclaving, thus showing to be thermostable. A correlation between phytoalexin accumulation in mesocotyls and increasing amounts of protein on elicitor samples was observed.

  18. Comparison of in vitro activity of five antifungal agents against dermatophytes, using the agar dilution and broth microdilution methods Comparação da atividade in vitro de cinco agentes antifúngicos para dermatófitos, usando os métodos de diluição em ágar e microdiluição em caldo

    Directory of Open Access Journals (Sweden)

    Crystiane Rodrigues Araújo Mota

    2009-06-01

    Full Text Available The purpose of this study was to compare the agar dilution and broth microdilution methods for determining the minimum inhibitory concentration (MIC of fluconazole, itraconazole, ketoconazole, griseofulvin and terbinafine for 60 dermatophyte samples belonging to the species Trichophyton rubrum, Trichophyton mentagrophytes and Microsporum canis. The percentage agreement between the two methods, for all the isolates with O propósito do presente trabalho foi comparar os métodos de diluição em ágar e diluição em caldo para a determinação de concentração inibitória mínima de fluconazol, itraconazol, cetoconazol, griseofulvina e terbinafina para 60 amostras de dermatófitos pertencentes às espécies, Trichophyton rubrum, Trichophyton. mentagrophytes e Microsporum canis. A porcentagem de acordo entre os dois métodos para todos os isolados testados considerando-se valores < 2 diluições, foram de 91,6% para cetoconazol e para griseofulvina, de 88,3% para itraconazol, de 81,6% para terbinafina e de 73,3% para fluconazol. Uma concordância de 100% foi obtido para isolados de Trichophyton mentagrophytes avaliados com cetoconazol e griseofulvina. Desta forma, até que um método de referência seja padronizado para testar a suscetibilidade in vitro para os dermatófitos, os resultados semelhantes encontrados para os dois métodos fazem com que o método de diluição em ágar possa ser útil no teste de suscetibilidade para estes fungos filamentosos.

  19. Microbiological evaluation of sugarcane juice sold at street stands and juice handling conditions in São Carlos, São Paulo, Brazil Avaliação microbiológica de caldo de cana comercializado em ruas e condições de manuseio de manipuladores em São Carlos, São Paulo, Brasil

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    Aline Cristine Garcia Oliveira

    2006-05-01

    Full Text Available Fresh sugarcane juice is sold by street vendors without any heat treatment in São Carlos, São Paulo, Brazil. Twenty-four samples of point-of-sale juice were tested by standard methods to determine heterotrophic bacteria, total and thermo-tolerant coliform counts, Salmonella, and parasites in the juice. 25% of samples showed poor sanitary conditions, with thermo-tolerant coliform levels higher than allowed by Brazilian standards. Salmonella spp. and parasites were absent in all samples. Thermo-tolerant coliforms were detected on the hands of 37% of juice handlers, and heterotrophic bacterial counts reached 2.0 x 10³ cfu/per hand. Escherichia coli was detected in one hand sample, and no Salmonella spp. was detected. Screening questionnaires were used to interview the vendors, and 62% of interviewees were either unfamiliar with or failed to adopt adequate hygiene for food handling.O caldo de cana é recém-preparado e comercializado por manipuladores sem tratamento térmico em São Carlos, São Paulo, Brasil. Vinte e quatro amostras da bebida obtidas em condição de consumidor nos pontos de venda foram avaliadas utilizando-se métodos convencionais na determinação de bactérias heterótrofas, contagens de coliformes totais e termo-tolerantes, Salmonella spp. e parasitas. Observou-se que 25% das amostras apresentaram condições sanitárias insatisfatórias, com níveis de coliformes termo-tolerantes superiores aos permitidos pelos padrões brasileiros. Salmonella spp. e parasitas não foram detectados em nenhuma amostra. Em 37% das mãos de manipuladores do produto detectou-se coliformes termo-tolerantes e as contagens de organismos heterótrofos atingiu valores de 2,0x103UFC/por mão. Em uma amostra de mão detectou-se a presença de Escherichia coli e ausência de Salmonella spp. Utilizaram-se entrevistas por meio de questionários com os vendedores e 62% destes não admitiram conhecimento ou adoção de quaisquer práticas higi

  20. Avaliação das metodologias M.I.C.E.®, Etest® e microdiluição em caldo para determinação da CIM em isolados clínicos Evaluation of M.I.C.E.TM, Etest® and CLSI broth microdilution methods for antimicrobial susceptibility testing of nosocomial bacterial isolates

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    Eloiza Helena Campana

    2011-04-01

    Full Text Available INTRODUÇÃO: As fitas Oxoid® M.I.C.Evaluator® (M.I.C.E., Thermo Fisher Scientific, Basingstoke, UK, recém-lançadas no mercado brasileiro, representam uma alternativa rápida para a realização de testes de sensibilidade a antimicrobianos (TSA. OBJETIVO: Avaliar o desempenho da metodologia M.I.C.E. em relação à microdiluição em caldo (teste de referência e ao Etest® (BioMérieux, Marcy l'Étoile, France. Material e métodos: Foram selecionados 160 isolados bacterianos, sendo P. aeruginosa (20, Acinetobacter spp. (20, K. pneumoniae (20, E. coli (20, S. aureus (20, Staphylococcus coagulase-negativa (20, E. faecalis (20 e E. faecium (20. Os TSAs foram realizados por microdiluição em caldo, Etest e M.I.C.E., seguindo-se as recomendações do Clinical Laboratory Standards Institute (CLSI, 2009 e dos respectivos fabricantes. Os resultados foram interpretados segundo os critérios estabelecidos pelo CLSI e comparados por análise de regressão. RESULTADOS: Avaliando-se todas as combinações de antimicrobianos vs. a espécie bacteriana, o desempenho da metodologia M.I.C.E. foi muito bom, apresentando uma concordância geral (variação na concentração inibitória mínima [CIM] ± 1-log2 > 90%, exceto para cefotaxima (85% e vancomicina (76,3%, quando em comparação com os resultados da metodologia de referência. Quando comparado com o Etest, a metodologia M.I.C.E. apresentou concordância geral > 96%, com exceção para a combinação amoxicilina/ácido clavulânico (67,5%. CONCLUSÃO: Os resultados do TSA obtidos pela metodologia M.I.C.E. apresentaram boa correlação com aqueles obtidos pela microdiluição em caldo e pelo Etest, indicando que essa metodologia é uma alternativa rápida para a determinação da CIM pelos laboratórios de microbiologia clínica. Atenção especial deve ser dada á determinação da CIM para a combinação amoxicilina/ácido clavulânico.INTRODUCTION: The Oxoid® M.I.C.EvaluatorTM methodology (M

  1. Capacidade antioxidante celular da rutina frente ao dano oxidativo induzido em linhagens mutantes de Saccharomyces cerevisiae

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    George Laylson da Silva Oliveira

    2016-07-01

    Full Text Available A rutina é um tipo de flavonoide encontrado nas plantas e de grande interesse farmacológico, já que muitas propriedades têm sido atribuídas a rutina, incluindo antialérgica, anti-inflamatória, antitumoral e principalmente antioxidante. O objetivo deste estudo foi proporcionar um maior conhecimento sobre a capacidade antioxidante celular da rutina utilizando linhagens de S. cerevisiae proficiente e deficiente em defesas antioxidantes. As linhagens de S. cerevisiae (Sodwt, Sod1∆, Sod2∆, Sod1∆Sod2∆, Cat1∆, Sod1∆Cat1∆ foram expostas as várias concentrações da rutina em três diferentes condições de tratamento (pré-tratamento, co-tratamento e pós-tratamento e assim verificar se a rutina inibe o efeito oxidativo do peróxido de hidrogênio, permitindo o aumento da sobrevivência das linhagens testadas. Os resultados obtidos mostram que a rutina diminui significativamente os danos oxidativos nas linhagens de S. cerevisiae nas condições de pré-tratamento, co-tratamento e pós-tratamento, demonstrando que a rutina apresenta uma elevada capacidade antioxidante celular, sendo importante na proteção ao estresse oxidativo induzido.Palavras-chave: Rutina. S. cerevisiae. capacidade antioxidante. ABSTRACTCellular antioxidant capacity of rutin against the oxidative damage induced in mutant strains of Saccharomyces cerevisiaeRutin is a type of flavonoid found in plants and of great pharmacological interest since many properties have been attributed rutin, including antiallergic, antiinflammatory, antitumor and antioxidant primarily. The aim of this study was to provide greater insight into the cellular antioxidant capacity of rutin using strains of S. cerevisiae proficient and deficient in antioxidant defenses. The strains of S. cerevisiae (Sodwt, Sod1Δ, Sod2Δ, Sod1ΔSod2Δ, Cat1Δ, Sod1ΔCat1Δ were exposed to various concentrations of rutin in three different conditions of treatment (pre-treatment, co-treatment and post

  2. In vitro susceptibility testing of dermatophytes isolated in Goiania, Brazil, against five antifungal agents by broth microdilution method Teste de suscetibilidade in vitro de dermatófitos isolados em Goiânia, Brasil, contra cinco agentes antifúngicos pelo método de microdiluição em caldo

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    Crystiane Rodrigues Araújo

    2009-02-01

    Full Text Available The antifungal activities of fluconazole, itraconazole, ketoconazole, terbinafine and griseofulvin were tested by broth microdilution technique, against 60 dermatophytes isolated from nail or skin specimens from Goiania city patients, Brazil. In this study, the microtiter plates were incubated at 28 ºC allowing a reading of the minimal inhibitory concentration (MIC after four days of incubation for Trichophyton mentagrophytes and five days for T. rubrum and Microsporum canis. Most of the dermatophytes had uniform patterns of susceptibility to the antifungal agents tested. Low MIC values as 0.03 µg/mL were found for 33.3%, 31.6% and 15% of isolates for itraconazole, ketoconazole and terbinafine, respectively.Atividades antifúngicas de fluconazol, itraconazol, cetoconazol, terbinafina e griseofulvina foram testadas pelo método de microdiluição em caldo contra 60 isolados de dermatófitos. Os resultados mostraram que todos os isolados produziram crescimento claramente detectável a 28 ºC e a concentração inibitória mínima (CIM foi determinada após quatro dias de incubação para Trichophyton mentagrophytes e cinco dias para T. rubrum e Microsporum canis. A maioria dos isolados teve um padrão uniforme de suscetibilidade para os agentes antifúngicos testados. Baixos valores de CIM como 0,03 µg/mL foram encontrados para 33,3%, 31,6% e 15% dos isolados para itraconazol, cetoconazol e terbinafina, respectivamente.

  3. Clinical <em>Saccharomyces cerevisiae em>isolates cannot cross the epithelial barrier <em>in vitroem>

    DEFF Research Database (Denmark)

    Pérez-Torrado, Roberto; Llopis, Silvia; Jespersen, Lene

    2012-01-01

    Saccharomyces cerevisiae is generally considered to be a safe organism and is essential to produce many different kinds of foods as well as being widely used as a dietary supplement. However, several isolates, which are genetically related to brewing and baking yeasts, have shown virulent traits,...

  4. Systematic and pathologic study of Paratanaisia bragai (Santos, 1934 Freitas, 1959 (Digenea, Eucotylidae infestation in ruddy ground dove Columbina talpacoti (Temminck, 1811 Estudo da sistemática e da patologia de Paratanaisia bragai (Santos, 1934 Freitas, 1959 (Digenea, Eucotylidae em rolinha-caldo-de-feijão, Columbina talpacoti (Temminck, 1811

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    R.M. Pinto

    2004-08-01

    Full Text Available This is the first report of the digenetic trematode Paratanaisia bragai infestation in a ruddy ground dove Columbina talpacoti, captured in a suburban area of Rio de Janeiro, Brazil. Although with a low prevalence (10%, the intensity of infection was high, considering that 116 worms were recovered from one of the kidneys. Gross lesions were not observed and histopathological analysis showed very dilated renal collecting ducts with destruction and flattening of the lining epithelial cells, without inflammatory reaction. The pathological findings were compared to those previously reported for P. bragai in other hosts, since the proposal of the species in 1934.O trematódeo digenético Paratanaisia bragai é referido pela primeira vez parasitando a rolinha-caldo-de-feijão, Columbina talpacoti, proveniente de área suburbana do Rio de Janeiro, Brasil. Embora com baixa prevalência (10%, a intensidade de infecção foi alta, considerando que 116 exemplares do parasito foram obtidos de um dos rins. Não foram observadas lesões macroscópicas. A análise histopatológica demonstrou grande dilatação dos dutos coletores renais, com destruição e achatamento das células epiteliais de revestimento, sem reação inflamatória. Os achados patológicos foram comparados aos anteriormente relatados para P. bragai em outros hospedeiros, desde a proposição da espécie em 1934.

  5. Avaliação de meios filtrantes primários em filtro contínuo de tambor rotativo a vácuo para lodo de caldo de cana Evaluation of primary filtering media in rotary vacuum drum filters for sugar-cane mud

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    Walter L. Polonio

    2006-04-01

    Full Text Available Este estudo teve o objetivo de avaliar o comportamento de treze tipos de meios filtrantes primários desenvolvidos para uso na filtração a vácuo de lodo de caldo de cana, simulando as operações de formação e desidratação da torta em filtros contínuos de tambor rotativo a vácuo, empregados nas indústrias de açúcar e álcool do Brasil. Para tanto, foi desenvolvida uma planta-piloto anexa ao filtro de tambor rotativo a vácuo, na qual foram realizados todos os ensaios, com o objetivo de refletir a realidade das variáveis operacionais durante uma safra sucroalcooleira. Os resultados são apresentados, comparando-se as taxas de filtração, variando a pressão de formação da torta, temperatura e concentração de auxiliar filtrante, mostrando ao usuário um novo caminho para o melhoramento quantitativo e qualitativo, sem aumentar a área nominal da unidade de filtração.This study aimed to evaluate the behavior or thirteen primary filtering media developed for to use in vacuum filtration of sugar-cane mud, simulating the formation and dewatering operations of the cake in Rotary Vacuum Drum Filters, applied in Sugar and Alcohol Mills in Brazil. For such, a pilot plant was attached to the Rotary Vacuum Drum Filter where all the essays took place, aiming to reflect the reality of the operation variables along the sugar and alcohol harvest. The results are shown with the comparison of filtration indexes, varying the cake formation pressure, the temperature and the concentration of the filtering auxiliary, giving the user a new way for quantitative and qualitative improvement, without the need to increase the nominal area of the filtering unity.

  6. Flavour compound production by <em>Yarrowia lipolyticaem>,> Saccharomyces cerevisiae em>and <em>Debaryomyces hansenii em>in a cheese-surface model

    DEFF Research Database (Denmark)

    Sørensen, Louise Marie; Gori, Klaus; Petersen, Mikael Agerlin

    2011-01-01

    produced sulphides, furanes and short-chain ketones; Saccharomyces cerevisiae D7 primarily produced esters and Debaryomyces hansenii D18335 primarily produced branched-chain aldehydes and alcohols. For several of the detected flavour compounds, an increase in production was observed upon exposure to dairy......A simple cheese model mimicking a cheese surface was developed for the detection of cheese flavour formation of yeasts. A total of 56 flavour compounds were detected by dynamic headspace sampling followed by gas chromatography - mass spectrometry analysis. Yarrowia lipolytica CBS2075 primarily...

  7. Proteome-wide analysis of lysine acetylation suggests its broad regulatory scope in <em>Saccharomyces cerevisiae>

    DEFF Research Database (Denmark)

    Henriksen, Peter; Wagner, Sebastian Alexander; Weinert, Brian Tate;

    2012-01-01

    Post-translational modification of proteins by lysine acetylation plays important regulatory roles in living cells. The budding yeast Saccharomyces cerevisiae is a widely used unicellular eukaryotic model organism in biomedical research. S. cerevisiae contains several evolutionary conserved lysin...

  8. Optimization of ordered plasmid assembly by gap repair in <em>Saccharomyces cerevisiae>

    DEFF Research Database (Denmark)

    Eckert-Boulet, Nadine Valerie; Pedersen, Mette Louise; Krogh, Berit Olsen;

    2012-01-01

    Combinatorial genetic libraries are powerful tools for diversifying and optimizing biomolecules. The process of library assembly is a major limiting factor for library complexity and quality. Gap repair by homologous recombination in Saccharomyces cerevisiae can facilitate in vivo assembly of DNA...... fragments sharing short patches of sequence homology, thereby supporting generation of high-complexity libraries without compromising fidelity. In this study, we have optimized the ordered assembly of three DNA fragments into a gapped vector by in vivo homologous recombination. Assembly is achieved by co......-transformation of the DNA fragments and the gapped vector, using a modified lithium acetate protocol. The optimal gap-repair efficiency is found at a 1:80 molar ratio of gapped vector to each of the three fragments. We measured gap-repair efficiency in different genetic backgrounds and observed increased efficiency...

  9. Reflexos da clarificação do caldo de cana com moringa sobre compostos inorgânicos do açúcar VHP

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    Gustavo H. G. Costa

    2015-02-01

    Full Text Available Objetivou-se, neste trabalho, avaliar os reflexos da clarificação do caldo de cana utilizando extrato de folhas e sementes de moringa (Moringa oleifera Lamarck como auxiliares de sedimentação sobre os teores dos compostos inorgânicos do caldo clarificado e do açúcar VHP (Very High Purity - Tipo Exportação produzido. O delineamento experimental utilizado foi o fatorial 5 x 2 com quatro repetições; o primeiro fator correspondeu aos auxiliares de sedimentação: extrato de folhas e sementes de moringa, polieletrólito sintético e testemunha; já o segundo fator correspondeu a duas variedades de cana-de-açúcar: RB92579 e RB867515. O caldo extraído foi clarificado através de caleagem simples, concentrado até 60 oBrix e submetido ao processo de cozimento. No caldo original, clarificado e no açúcar produzido, foram quantificados os teores de fósforo, potássio, cálcio, sódio, magnésio, manganês e ferro além do teor de cinzas totais. Os empregos dos extratos de folhas e sementes de moringa se mostraram eficazes no tratamento do caldo destinado à produção de açúcar, por eliminar quantidades significativas de cálcio e ferro em comparação ao polieletrólito sintético. O extrato de folhas foi o melhor auxiliar de sedimentação,quando comparado aos demais.

  10. Influência de frações da parede celular de levedura (Saccharomyces cerevisiae) sobre alguns parâmetros nutricionais de ratos em crescimento

    OpenAIRE

    Chaud,Saula Goulart; Sgarbieri,Valdemiro Carlos; Vicente, Eduardo

    2008-01-01

    OBJETIVO: O objetivo deste trabalho foi avaliar a influência das frações de parede celular de levedura (Saccharomyces cerevisiae) sobre alguns parâmetros nutricionais de ratos Wistar em crescimento. MÉTODOS: A biomassa de levedura (Saccharomyces cerevisiae), coletada sem sofrer o processo de termólise, foi recebida da usina São José, Zillo Lorenzetti (Macatuba, SP), em suspensão de, aproximadamente, (20% p/v) de células. O fracionamento da parede celular da levedura foi realizado por extração...

  11. Recombinant Production of Human Aquaporin-1 to an Exceptional High Membrane Density in <em>Saccharomyces> <em>cerevisiae>

    DEFF Research Database (Denmark)

    Bomholt, Julie; Helix Nielsen, Claus; Scharff-Poulsen, Peter;

    2013-01-01

    In the present paper we explored the capacity of yeast Saccharomyces cerevisiae as host for heterologous expression of human Aquaporin-1. Aquaporin-1 cDNA was expressed from a galactose inducible promoter situated on a plasmid with an adjustable copy number. Human Aquaporin-1 was C-terminally tag......In the present paper we explored the capacity of yeast Saccharomyces cerevisiae as host for heterologous expression of human Aquaporin-1. Aquaporin-1 cDNA was expressed from a galactose inducible promoter situated on a plasmid with an adjustable copy number. Human Aquaporin-1 was C...... and generated a monodisperse protein preparation. A single Ni-affinity chromatography step was used to obtain almost pure Aquaporin-1. Recombinant Aquaporin-1 produced in S. cerevisiae was not N-glycosylated in contrast to the protein found in human erythrocytes....

  12. A Composição do caldo de cana de açúcar: Contribuição para o estudo dos efeitos de adubações

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    S. C. Sampaio

    1945-05-01

    Full Text Available Analisando-se o que vimos de expor, para as condições experimentadas, verifica-se o seguinte : 1. Os diversos elementos fertilizantes comumente aplicados às culturas cana vieiras exerceram alguma influência sôbre a rigueza e a pureza do caldo. 2. Os adubos nitrogenados, em geral, deprimiram o teor em sacarose do caldo, assim como prejudicaram a sua pureza, e isto se dá tanto nas terras coloridas como nas arenosas, claras. 3. Os fertilizantes potássicos, em conjunto, favoreceram a formação do açúcar no caldo, não se notando o mesmo efeito nítido na melhoria da pureza do mesmo. Nas terras roxas ou falsa-roxas a sua ação favorável foi acentuada tanto para o enriguecimento do caldo como para melhorar a pureza dêste ; mas, nas terras arenosas, claras, as cousas aconteceram às avessas. 4. Apreciando o efeito geral do fósforo, podemos notar que não teve êle a virtude de controlar a pureza. Apenas colaborou para melhorar os efeitos de N e de K ; mas a riqueza do caldo sofreu uma influência favorável, o que se acentuou na presença do calcáreo. O comportamento do adubo fosfatado não foi uniforme para os diferentes tipos de terra. Nas terras coloridas a sua contribuição foi medíocre para quaisquer melhorias da qualidade do caldo; nas terras arenosas, claras, entretanto, êle foi um fator nitidamente capaz de aumentar a sua riqueza em sacarose, o que se não modificou na presença do calcáreo ; mas isto não aconteceu com a mesma intensidade quanto à pureza, apesar de o elemento fósforo ter contribuído para melhorar os efeitos de N e de K, menos na interação NPK. 5. O calcáreo, englobadamente nos 6 ensaios aqui referidos, apresentou um balanço favorável, quanto ao enriquecimento do caldo em sacarose, de 3,01% ; mas, com referência à pureza, o seu efeito foi desfavorável, e de maneira nítida, com saldo deficitário de 10,64%. Examinando-se, porém, por partes, vê-se que, se o corretivo colabora valiosamente para a

  13. Produtividade do Sorgo granífero cv. sacarino e qualidade de produtos formulados isoladamente ou combinados ao caldo de cana-de-açúcar Yield of Sorghum bicolor cv. sacarino and quality of products formulated isolated or combined with sugar cane juice

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    Cassiara Camelo de Souza

    2005-09-01

    Full Text Available Este trabalho teve como objetivo avaliar o comportamento produtivo do Sorgo granífero (Sorghum bicolor L variedade IPA- 467, mediante condições de irrigação e adubação, bem como, a caracterização físico-química da farinha de diferentes tipos de grãos e de rapadura obtida a partir de combinações de caldo de sorgo (CS x caldo de cana (CC. O experimento resultou em uma produção de biomassa, sementes, colmo, caldo, melaço fino e melaço grosso, respectivamente, de: 64t/ha; 3,5t/ha; 46t/ha; 700L/t de colmo; 140L/t de colmo e 90L/t de colmo. A farinha obtida a partir de grãos de sorgo apresenta teor de açúcares totais inferior aos da farinha de trigo. As rapaduras em que o caldo de sorgo foi adicionado nas proporções de 10 e 20%, em associação com o caldo-de-cana, obtiveram maior nível de aceitação, quando comparada à rapadura obtida a partir de 100% de caldo de cana-de-açúcar. A aceitação de rapaduras formuladas a partir 30% de caldo sorgo e 70% de caldo de cana não diferiu de rapaduras obtidas de 100% de caldo de cana.The objective of this work was to evaluate the yield of Sorghum bicolor var. IPA-467, under irrigation and fertilizer conditions and the physical-chemical characterization of grain flours and 'rapadura' obtained from combinations of sorghum stem juice (SJ x sugar cane juice (CJ. The experiment resulted im biomass production, seeds, stem, juice, thick sugarcane syrup, respectively of 64t/ha; 3,5t/ha, 46t/ha, 700L/t of stem, 140L/t of stem and 90L/t of stem. The total sugars of sorghum grain flour were lower than results reported for wheat flour. 'Rapaduras' in which sorghum juice was used at 10 and 20, in combination of sugar cane juice, had higher acceptance scores, as compared with 'rapadura' obtaned from 100% sugar cane juice. The acceptance of 'rapaduras' formulated from 30% SJ x 70% CJ did not differ from those obtained from 100% CJ.

  14. Caracterización de grasas para caldos deshidratados

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    Correa-Cabrera, R.

    1999-02-01

    Full Text Available Fats represent a major part of the weight of dehydrated soup cubes. As these products are stored at room temperature, the fatty components should show no partial melting during the Summer months. Six fatty raw materials, mixtures of these fats already prepared by the manufacturer and lipidic extracts from the finished cubes (both hen and vegetables soups are analyzed in this work, trying to relate origin (fatty acid composition with stability against temperature changes (DSC thermogram. Some of the studied fats are found acceptable according to the expected shelf life of the product, although others should be modified before usage, either by fractioning or by hydrogenation.

    Las grasas constituyen un alto porcentaje del peso de los caldos deshidratados envasados bajo forma de cubitos. Como estos alimentos se almacenan a temperatura ambiente, sus componentes grasos no deben fundir parcialmente durante el verano. En este trabajo se analizan seis muestras de materias primas grasas, mezclas de ellas ya preparadas por la empresa elaboradora y extractos lipidióos del producto terminado (sopas de gallina y de verduras. Se busca relacionar la naturaleza de las grasas (composición en ácidos grasos con su estabilidad frente a variaciones de la temperatura (termogramas por DSC. Se concluye que, si bien algunas de las grasas estudiadas son aceptables desde el punto de vista de la vida útil esperada del producto, otras se deberían modificar por hidrogenación o fraccionamiento antes de su uso.

  15. Susceptibility of Saccharomyces cerevisiae and lactic acid bacteria from the alcohol industry to several antimicrobial compounds Susceptibilidade de Saccharomyces cerevisiae e bactérias láticas provenientes de indústrias alcooleiras a vários compostos antimicrobianos

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    Pedro de Oliva-Neto

    2001-03-01

    Full Text Available The antimicrobial effect of several products including commercial formulations currently used in sugar and alcohol factories was determined by adapted MIC (Minimal Inhibitory Concentration test on Saccharomyces cerevisiae and on natural contaminants Lactobacillus fermentum and Leuconostoc mesenteroides. The MIC test by macrodilution broth method was adapted by formulating of the culture medium with cane juice closely simulating industrial alcoholic fermentation must. Acid penicillin V (MIC 0.10-0.20 µg/ml and clindamycin (MIC 0.05-0.40 µg/ml were most effective against bacterial growth in 24 h. Among the chemicals, sulphite (MIC 10-40 µg/ml, nitrite (MIC 50 µg/ml. Methyldithiocarbamate was efficient only on L. fermentum (MIC 2.5 µg/ml and S. cerevisiae (MIC 5.0 µg/ml. Thiocianate (MIC 1.2-5.0 µg/ml, bromophenate (MIC 9-18 µg/ml and n- alkyldimethylbenzylammonium cloride (MIC 1-8 µg/ml affected S. cerevisiae at similar inhibitory concentration for L. mesenteroides or L. fermentum. Formaldehyde was more effective on bacteria (MIC 11.5 - 23 µg/ml in both pH (4.5 and 6.5 than yeast (MIC 46-92 µg/ml. Several tested formulated biocides seriously affect S. cerevisiae growth in the similar dosages of the bacterial inhibition, so these products should be avoided or used only in special conditions for the bacterium control of fermentation process. For this step, the control of these contaminants by antibiotics are more suitable and effective.O efeito antimicrobiano de vários produtos incluindo formulações comerciais usualmente utilizadas em usinas de açúcar e álcool foi determinado pelo teste da Concentração Mínima Inibitória (CMI adaptada para Saccharomyces cerevisiae e os contaminantes naturais Lactobacillus fermentum and Leuconostoc mesenteroides. O teste da CMI foi feito pela adaptação do método da Macrodiluição em caldo pela formulação de um meio de cultivo com caldo de cana em condições similares ao mosto da fermenta

  16. Implication of Ccr4-Not complex function in mRNA quality control in <em>Saccharomyces cerevisiae>

    DEFF Research Database (Denmark)

    Assenholt, Jannie; Mouaikel, John; Saguez, Cyril

    2011-01-01

    Production of messenger ribonucleoprotein particles (mRNPs) is subjected to quality control (QC). In Saccharomyces cerevisiae, the RNA exosome and its cofactors are part of the nuclear QC machinery that removes, or stalls, aberrant molecules, thereby ensuring that only correctly formed mRNPs are ......Production of messenger ribonucleoprotein particles (mRNPs) is subjected to quality control (QC). In Saccharomyces cerevisiae, the RNA exosome and its cofactors are part of the nuclear QC machinery that removes, or stalls, aberrant molecules, thereby ensuring that only correctly formed m......RNPs are exported to the cytoplasm. The Ccr4-Not complex, which constitutes the major S. cerevisiae cytoplasmic deadenylase, has recently been implied in nuclear exosome–related processes. Consistent with a possible nuclear function of the complex, the deletion or mutation of Ccr4-Not factors also elicits...... transcription phenotypes. Here we use genetic depletion of the Mft1p protein of the THO transcription/mRNP packaging complex as a model system to link the Ccr4-Not complex to nuclear mRNP QC. We reveal strong genetic interactions between alleles of the Ccr4-Not complex with both the exosomal RRP6 and MFT1 genes...

  17. Identification of novel GAPDH-derived antimicrobial peptides secreted by <em>Saccharomyces cerevisiae> and involved in wine microbial interactions

    DEFF Research Database (Denmark)

    Branco, Patrícia; Francisco, Diana; Chambon, Christophe

    2014-01-01

    Saccharomyces cerevisiae plays a primordial role in alcoholic fermentation and has a vast worldwide application in the production of fuel-ethanol, food and beverages. The dominance of S. cerevisiae over other microbial species during alcoholic fermentations has been traditionally ascribed to its ...

  18. Fermentação de trealose e glicogênio endógenos em Saccharomyces cerevisiae Fermentation of endogenous trehalose and glycogen by Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    L.V. FERREIRA

    1999-01-01

    Full Text Available As linhagens PE-2 e VR-1 de Saccharomyces cerevisiae foram submetidas à fermentação das reservas endógenas na temperatura de 40oC. No intervalo de 0 a 24 horas foram recolhidas as amostras para a determinação de etanol, nitrogênio no fermento e no vinho, bem como os carboidratos de reserva (trealose e glicogênio e a viabilidade celular. A trealose foi esgotada durante 24 horas. Os teores de glicogênio sofreram muitas oscilações ao longo do tempo, entre a mobilização e a síntese e embora não esgotado, deve ter contribuído significativamente para a formação de álcool na suspensão. Foi observada a relação proporcional entre a mobilização de trealose e a queda da viabilidade celular. No transcorrer da fermentação das reservas de carboidratos houve aumento nos teores de nitrogênio no fermento até 6 e 8 horas, sendo tal incremento afetado pela linhagem de levedura. No prosseguimento da fermentação ocorreu a autólise celular, que foi percebida pelo aumento brusco de nitrogênio no vinho (de 200 para 1500mg/L e pela queda da viabilidade celular. O ganho alcançado com a fermentação endógena foi de 40 e 68 litros de álcool por tonelada de levedura seca com incremento de 25 e 27% de proteína no fermento para as linhagens PE-2 e VR-1, respectivamente. Este resultado tem reflexos positivos quando da comercialização da levedura seca como proteína microbiana.Two Saccharomyces cerevisiae strains (PE-2 and VR-1 were subjected to fermentation of its carbohidrate reserve (Trehalose and glycogen at 40oC. During a 24 hours interval samples were collected for determination of ethanol, yeast and wine nitrogen, yeast trehalose, glycogen and cell viability. Trehalose was completely exhausted after 24 hours. Glycogen was not completely consumed, but probably contributes for ethanol formation. As trehalose is consumed yeast cell viability decreases, while yeast nitrogen content increase, reaching a maximum between 6 and 8 hours

  19. Regulation of Saccharomyces cerevisiae maltose fermentation by cold temperature and CSF1 Regulação da fermentação de maltose em Saccharomyces cerevisiae por baixas temperaturas e CSF1

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    Claudia Hollatz

    2003-11-01

    Full Text Available We studied the influence of cold temperature (10ºC on the fermentation of maltose by a S. cerevisiae wild-type strain, and a csf1delta mutant impaired in glucose and leucine uptake at low temperatures. Cold temperature affected the fermentation kinetics by decreasing the growth rate and the final cell yield, with almost no ethanol been produced from maltose by the wild-type cells at 10ºC. The csf1delta strain did not grew on maltose when cultured at 10ºC, indicating that the CSF1 gene is also required for maltose consumption at low temperatures. However, this mutant also showed increased inhibition of glucose and maltose fermentation under salt stress, indicating that CSF1 is probably involved in the regulation of other physiological processes, including ion homeostasis.Foi estudado o efeito da baixa temperatura (10ºC na fermentação de maltose por uma cepa de S. cerevisiae selvagem, e uma cepa csf1delta mutante incapaz de transportar glicose e leucina a baixas temperaturas. A baixa temperatura afeta a cinética da fermentação por diminuir a velocidade de crescimento e rendimento celular final, com quase nenhum etanol produzido a partir de maltose pelas células selvagems a 10ºC. A cepa csf1delta foi incapaz de crescer em maltose a 10ºC, indicando que o gene CSF1 é também necessário para a utilização de maltose a baixas temperaturas. Entretanto, o mutante também mostrou inibição acentuada da fermentação de glicose e maltose por estresse salino, indicando que CSF1 também estaria envolvido na regulação de outros processos fisiológicos, incluindo a homeostase iónica.

  20. Fontes nitrogenadas e uso de Sacharomyces cerevisiae em dietas à base de cana-de-açúcar para novilhos: consumo, digestibilidade, balanço nitrogenado e parâmetros ruminais

    Directory of Open Access Journals (Sweden)

    Pereira Elzânia Sales

    2001-01-01

    Full Text Available O objetivo do presente estudo foi avaliar os efeitos das fontes nitrogenadas e o uso de Sacharomyces cerevisiae em dietas à base de cana-de-açúcar sobre os consumos e as digestibilidades aparentes totais e parciais de matéria seca (MS, matéria orgânica (MO, proteína bruta (PB, extrato etéreo (EE, carboidratos totais (CHO, fibra em detergente neutro (FDN e carboidratos não-estruturais (CNE, o balanço nitrogenado e os parâmetros ruminais. Foram utilizados quatro novilhos Holandês-Zebu, fistulados no rúmen e abomaso, alimentados com quatro rações à base de cana-de-açúcar, constituídas de duas fontes nitrogenadas (uréia ou cama de frango combinadas com dois níveis de Sacharomyces cerevisiae (0 e 10 g/dia. Utilizou-se delineamento em quadrado latino 4 x 4. A fibra em detergente neutro indigestível (FDNi foi utilizada como indicador, para determinar as digestibilidades aparentes totais e parciais. Os consumos de MS, MO, EE, CT e CNE não foram influenciados pelas fontes nitrogenadas e pela utilização de Sacharomyces cerevisiae. Os consumos de PB e FDN foram maiores para as dietas suplementadas com cama de frango. Os coeficientes de digestibilidades totais de PB e EE foram maiores para as dietas constituídas de uréia. As digestibilidades aparentes totais de MS, MO, CT e FDN não foram influenciadas pelas fontes nitrogenadas e pela utilização de Sacharomyces cerevisiae. O pH do líquido ruminal decresceu linearmente para as dietas suplementadas com uréia e apresentou comportamento quadrático, quando estas dietas foram combinadas com Sacharomyces cerevisiae. As concentrações de amônia no líquido ruminal apresentaram comportamento quadrático, estimando-se valores máximos de 16,90; 26,12; 18,48; e 14,40 mg/100 mL para os tratamentos constituídos de cana-de-açúcar e uréia; cana-de-açúcar, uréia e Sacharomyces cerevisiae; cana-de-açúcar e cama de frango; e cana-de-açúcar, cama de frango e Sacharomyces cerevisiae

  1. The Flo11p-deficient <em>Saccharomyces cerevisiae> strain background S288c can adhere to plastic surfaces

    DEFF Research Database (Denmark)

    Mortensen, Henrik Dam; Dupont, Kitt; Jespersen, Lene;

    2007-01-01

    The effects of four types of plastic surfaces and four pre-incubation media, containing high/low glucose and +/- amino acids, on adhesion of Saccharomyces cerevisiae BY4742 wild type and Deltaflo11 mutant (strain background S288c) were investigated. No difference in adhesive ability between the two...... yeast strains was observed in any of our experiments, thus confirming that FLO11 is not operational in the S. cerevisiae S288c strain background. The adhesive abilities of both yeast strains depended on the plastic type and pre-incubation conditions. The poorest adhesion was observed on hydrophilic...... hydrophobicity and enhanced the adhesion to all four types of polystyrene. Lack of amino acids in the pre-incubation media increased the cell surface hydrophobicity and enhanced the adhesion especially to polystyrene surfaces with combined hydrophilic/hydrophobic domains. Our results suggest that glucose...

  2. Evaluation of potential immunostimulant of the Carboxymethyl-glucan from Saccharomyces cerevisiae in poultry (Gallus domesticus / Avaliação do potencial imunoestimulante da Carboximetil-glucana de Saccharomyces cerevisiae em frangos de corte (Gallus domesticus

    Directory of Open Access Journals (Sweden)

    Raul Jorge Hernan Castro-Goméz

    2010-04-01

    Full Text Available The carboxymethylglucan (CMG is a soluble molecule, composed of glucopyranosyl linked by ?(1-3 e ?(1-6, which can activate the immune system of the host. The purpose of this study was evaluate the productive and immunological characteristics of 192 poultry (Gallus domesticus COBB line which received feds containing 0%, 0,025%, 0,050% e 0,075% of CMG from Saccharomyces cerevisiae added in corn flour. All poultry were immunized against Newcastle disease and at each treatment 3 poultries randomly chosen received CMG intramuscular at 3, 7 and 14 days. It was evaluated the animal performance, development of the bursa of Fabricius, histological slides of the small intestine, counts of phagocytes cells in blood and levels of antibodies in serum. The results showed difference in weight gain and consumption of feed to poultry that consumed CMG at 1 to 21 days. Fabricius bursa relative weight increased in poultry supplemented with 0,025 e 0,050% of CMG. The phagocytic cells number and total levels of antibodies found in poultry at 21 days were higher in those that received CMG in the diet. For the animals that received intramuscular CMG was observed increase of antibodies specific to Newcastle.A carboximetilglucana (CMG é uma molécula solúvel, composta de resíduos de glicopiranosil unidos em ?(1-3 e ?(1-6, que possui a capacidade de ativar o sistema imune do hospedeiro. O objetivo do presente estudo foi avaliar as características produtivas e imunológicas de 192 frangos de corte (Gallus domesticus da linhagem COBB, que receberam rações contendo 0%, 0,025%, 0,050% e 0,075% de CMG de Saccharomyces cerevisiae adicionada em farinha de milho. Todas as aves foram imunizadas contra a doença de Newcastle e, em cada tratamento, 3 aves escolhidas aleatoriamente receberam CMG intramuscular no 3º, 7º e 14º dia. Foram avaliados o desempenho animal, o desenvolvimento da bursa de Fabricius e lâminas histológicas do intestino delgado, além do número de c

  3. Efeitos do cádmio sobre o crescimento das leveduras Saccharomyces cerevisiae PE-2 e Saccharomyces cerevisiae IZ-1904, e a capacidade da vinhaça em atenuar a toxicidade Effect of cadmium on the growth of two Saccharomyces cerevisiae strains, and the vinasse capacity to atenuate the toxicity

    Directory of Open Access Journals (Sweden)

    Samuel Mariano-da-Silva

    2004-03-01

    Full Text Available O presente trabalho teve por finalidade estudar os efeitos do cádmio sobre a levedura Saccharomyces cerevisiae, bem como avaliar a possibilidade de se utilizar a vinhaça como fornecedora de agentes ligantes, visando minimizar os efeitos deletérios do mesmo. Primeiramente montou-se um ensaio visando observar a ação tóxica de diferentes concentrações de cádmio (0; 0,05; 0,1 e 0,5mM, avaliada pelo crescimento de duas cepas da levedura S. cerevisiae (PE-2 e IZ-1904 em meio YED. O meio foi inoculado com 1mL de uma suspensão a 1% (m/v das respectivas cepas e incubado por 18 horas. Em tempos determinados durante o crescimento anaeróbio, alíquotas da suspensão de células foram retiradas e a concentração celular foi determinada. No final do ensaio, foram determinadas a viabilidade celular, a taxa de brotamento e a contaminação bacteriana. Os teores de trealose para cada tratamento, de ambas as cepas, foram dosados no início e no final do ensaio. Em uma segunda etapa, montou-se um ensaio visando avaliar a capacidade da vinhaça (0,15 e 30% do volume do meio em atenuar os efeitos tóxicos de duas doses de cádmio (0,1 e 0,5mM, empregando-se a levedura S. cerevisiae PE-2 em meio YED. O meio foi inoculado com 2mL de uma suspensão a 1% (m/v da levedura e incubado por 18 horas. Em tempos determinados durante o crescimento anaeróbio, alíquotas da suspensão de células foram retiradas e a concentração celular foi determinada. No final do ensaio, foram determinadas a viabilidade celular, a taxa de brotamento, a contaminação bacteriana e a produção de etanol. Os teores de trealose, para cada tratamento, foram dosados nas leveduras no início e no final do ensaio. O cádmio prejudicou o crescimento e a viabilidade celular das duas cepas da levedura S. cerevisiae. A vinhaça apresentou um discreto efeito tóxico, traduzido pela redução do crescimento. Porém, nos tratamentos contaminados com cádmio, apresentou um efeito protetor

  4. Avaliação de compostos com atividade antioxidante em células da levedura Saccharomyces cerevisiae Evaluation of compounds with antioxidant activity in Saccharomyces cerevisiae yeast cells

    Directory of Open Access Journals (Sweden)

    Daniele Grazziotin Soares

    2005-03-01

    Full Text Available Antioxidantes são compostos que atuam inibindo e/ou diminuindo os efeitos desencadeados pelos radicais livres e compostos oxidantes. Diferentes métodos têm sido desenvolvidos para obter a diferenciação, seja qualitativa ou quantitativa, da capacidade antioxidante de compostos, tanto através de testes sem a utilização de células (testes químicos ou utilizando culturas celulares (testes biológicos. Os testes químicos são mais rápidos e simples de serem executados. No entanto, não são representativos das condições celulares do homem. Ensaios microbianos `in vivo' utilizando-se, principalmente, células eucarióticas da levedura Saccharomyces cerevisiae têm se mostrado muito adequados para determinação da capacidade antioxidante de diferentes compostos, fornecendo resultados rápidos, reprodutíveis e passíveis de serem correlacionados ao observado no homem. O objetivo deste trabalho foi avaliar a capacidade antioxidante do ácido L-ascórbico, vitamina E (alfa-tocoferol e dos flavonóides hesperidina, naringina, naringenina, quercetina, rutina e sakuranetina, utilizando como modelo de sistema biológico a levedura S. cerevisiae. Para realização dos testes, as células foram tratadas com o agente estressor apomorfina em presença e ausência das amostras. Os resultados mostraram que a rutina, hesperidina, sakuranetina, quercetina e naringina foram os compostos com maior atividade antioxidante, seguidos da naringenina e vitamina E. O ácido L-ascórbico e a mistura de ácido L-ascórbico e vitamina E não mostraram atividade antioxidante frente aos danos gerados pela apomorfina nas concentrações ensaiadas.Antioxidants are compounds that remove free-radicals or minimize their availability to generate oxidative stress. There are many methods to determine antioxidant capacity, but microbiological assays, using mainly eukaryotic cells, have shown similar results to man. The purpose of this work was to evaluate, through

  5. Folhas verdes, folhas secas, fibra do colmo e a clarificação do caldo de cana-de-açúcar Green leaves, dry leaves, stalk fiber and the clarification of sugarcane juice

    Directory of Open Access Journals (Sweden)

    Roberto Bovi

    2001-09-01

    Full Text Available A presença de impurezas vegetais, como folhas verdes e secas, nos carregamentos de cana-de-açúcar entregues nas usinas de açúcar, tem preocupado os técnicos não somente por se tratar de um material sem qualquer valor tecnológico para processamento, como ainda por poder causar aumento na cor do caldo clarificado e conseqüentemente na cor do açúcar produzido, com redução de sua qualidade para o mercado; outro problema é o volume do lodo decantado nos clarificadores, cujo aumento causa maior recirculação e maior volume do caldo filtrado, com maiores perdas de sacarose e maior utilização dos filtros rotativos a vácuo. O trabalho teve como objetivo avaliar a clarificação do caldo de cana-de-açúcar com a adição de folhas verdes e folhas secas, tendo como controle a adição de fibra do colmo. Os ensaios foram delineados tendo como base a adição de quantidades das fontes fibrosas - folha verde, folha seca e fibra do colmo - para formular amostras que correspondessem a acréscimos absolutos de 0,25 , 0,50 e 0,75 ponto percentual sobre o teor de fibra do colmo da cana. Os efeitos sobre a clarificação do caldo, conduzida em clarificador de bancada em laboratório, foram avaliados pela cor do caldo clarificado e o volume de lodo decantado. Na presença de folhas verdes ocorreu uma elevação da cor do caldo clarificado e do volume de lodo decantado. Da folha verde são extraídos água e compostos que são responsáveis por alterações na composição do caldo; devido à presença de componentes não-sacarose o extrato foliar interfere na clarificação do caldo. Da folha seca também foram extraídos compostos solúveis, todavia não detectados através das análises do caldo. A fibra do colmo não afetou a clarificação.The presence of vegetal impurities in sugarcane delivered to sugarmills as green and dry leaves is a problem not only because they are non-value materials to be processed along with sugarcane stalks, but

  6. Alterações na atividade e no perfil eletroforético da peroxidase em folhas de milho (Zea mays e sorgo (Sorghum bicolor tratadas com levedura (Saccharomyces cerevisiae Change in activity and electrophoretic pattern of peroxidase in maize (Zea mays and sorghum (Sorghum bicolor leaves after treatment with yeast (Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    M.C. RONCATTO

    1998-01-01

    Full Text Available O trabalho foi desenvolvido com o objetivo de se verificar a influência de Saccharomyces cerevisiae na forma de produto comercial, fermento biológico fresco para panificação, na atividade e no padrão eletroforético da peroxidase em folhas de milho e sorgo. As preparações de Saccharomyces utilizadas foram representadas por suspensões de células e seus respectivos filtrados, autoclavados ou não. A análise dos extratos obtidos dessas gramíneas mostrou que suspensões de células e os filtrados dessas suspensões, tratadas termicamente ou não, foram efetivos em ocasionar alterações na atividade e padrão eletroforético da peroxidase em milho e sorgo. Além de se mostrarem termoestáveis, os extratos obtidos de células intactas ou homogeneizadas de S. cerevisiae apresentaram baixa atividade de peroxidase, indicando que as alterações na atividade e perfil eletroforético da enzima nas plantas eram decorrentes do próprio tecido vegetal. Finalmente, os resultados sugerem que as alterações ocorridas com a peroxidase nas gramíneas estudadas, em resposta ao tratamento com S. cerevisiae, refletem o "reconhecimento" das células ou metabólitos da levedura por parte das plantas, acarretando uma alteração no metabolismo normal das mesmas.The aim of this work was to test the effect of Saccharomyces cerevisiae, in a commercial baker's yeast form, on the activity and changes in the electrophoretic pattern of peroxidase in maize and sorghum leaves. The yeast treatment included spray of cell suspensions and their filtrates, autoclaved or not, which were able to cause changes in the peroxidase activity and electrophoretic pattern in maize and sorghum. Besides being thermostable, the extracts from intact or homogenized S. cerevisiae cells exhibited low peroxidase activity, indicating that the changes in the enzyme, activity and pattern, were due only to the plant tissue. Finally, the results suggest that the changes in peroxidase in maize

  7. Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Bojsen, Rasmus K; Andersen, Kaj Scherz; Regenberg, Birgitte

    2012-01-01

    Microbial biofilms can be defined as multi-cellular aggregates adhering to a surface and embedded in an extracellular matrix (ECM). The nonpathogenic yeast, Saccharomyces cerevisiae, follows the common traits of microbial biofilms with cell-cell and cell-surface adhesion. S. cerevisiae is shown...... pathways including the protein kinase A and a mitogen-activated protein kinase pathway. Advanced genetic tools and resources have been developed for S. cerevisiae including a deletion mutant-strain collection in a biofilm-forming strain background and GFP-fusion protein collections. Furthermore, S....... cerevisiae biofilm is well applied for confocal laser scanning microscopy and fluorophore tagging of proteins, DNA and RNA. These techniques can be used to uncover the molecular mechanisms for biofilm development, drug resistance and for the study of molecular interactions, cell response to environmental...

  8. Avaliação da qualidade do caldo extraído de toletes de cana-de-açúcar minimamente processada, armazenados sob diferentes temperaturas Evaluation of the quality of the juice extracted of pieces of fresh cut sugar cane stored under different temperatures

    Directory of Open Access Journals (Sweden)

    Silvana Rodrigues Rabelo de Andrade

    2008-12-01

    Full Text Available O presente trabalho visou avaliar a qualidade físico-química e microbiológica do caldo extraído de toletes de cana-de-açúcar minimamente processada, armazenados sob três temperaturas. Colmos de cana-de-açúcar foram minimamente processados na forma de toletes com 60 cm de comprimento, higienizados e acondicionados em embalagens de polietileno de baixa densidade. Cada embalagem acondicionou 12 toletes de cana-de-açúcar devidamente higienizados. Em seguida, procedeu-se o armazenamento das embalagens sob três temperaturas: ambiente (22 a 25 °C, utilizada como controle, refrigeração (4 °C e congelamento (-20 °C. Foram avaliadas a qualidade físico-química do caldo e a sua composição microbiológica, em intervalos de 6 dias, durante 24 dias de armazenamento. O caldo extraído dos toletes armazenados sob congelamento apresentou boa qualidade físico-química e microbiológica durante todo o período avaliado. Por outro lado, o caldo extraído dos toletes armazenados sob refrigeração e o controle apresentaram elevadas alterações microbiológicas, limitando o período de conservação dos toletes até 12 e 6 dias, respectivamente, o que permitiu concluir que o tratamento mais eficiente para a preservação da qualidade do caldo foi o congelamento da cana-de-açúcar minimamente processada.The present work aimed at evaluating the microbiological and physicochemical quality of fresh cut sugar cane juice. Sugar cane stalks were cut in pieces of 60 cm of length, sanitized, and conditioned in polyethylene packaging of low density. Each package conditioned 12 pieces of sanitized sugar can. After that, they were stored at three different temperatures: room temperature (22-25 °C, used as control, refrigeration (4 °C, and freezing (-20 °C. The microbiological and physicochemical quality of the juice was evaluated every 6 days of storage for 24 days. The sugar cane juice stored under freezing temperatures presented good quality for all

  9. Models for the a subunits of the Thermus thermophilus V/A-ATPase and Saccharomyces cerevisiae V-ATPase enzymes by cryo-EM and evolutionary covariance.

    Science.gov (United States)

    Schep, Daniel G; Zhao, Jianhua; Rubinstein, John L

    2016-03-22

    Rotary ATPases couple ATP synthesis or hydrolysis to proton translocation across a membrane. However, understanding proton translocation has been hampered by a lack of structural information for the membrane-embedded a subunit. The V/A-ATPase from the eubacterium Thermus thermophilus is similar in structure to the eukaryotic V-ATPase but has a simpler subunit composition and functions in vivo to synthesize ATP rather than pump protons. We determined the T. thermophilus V/A-ATPase structure by cryo-EM at 6.4 Å resolution. Evolutionary covariance analysis allowed tracing of the a subunit sequence within the map, providing a complete model of the rotary ATPase. Comparing the membrane-embedded regions of the T. thermophilus V/A-ATPase and eukaryotic V-ATPase from Saccharomyces cerevisiae allowed identification of the α-helices that belong to the a subunit and revealed the existence of previously unknown subunits in the eukaryotic enzyme. Subsequent evolutionary covariance analysis enabled construction of a model of the a subunit in the S. cerevisae V-ATPase that explains numerous biochemical studies of that enzyme. Comparing the two a subunit structures determined here with a structure of the distantly related a subunit from the bovine F-type ATP synthase revealed a conserved pattern of residues, suggesting a common mechanism for proton transport in all rotary ATPases.

  10. Breeding of saccharomyces cerevisiae with lower-level porteinase A by EMS mutation%甲基磺酸乙酯(EMS)诱变选育低产蛋白酶A啤酒酵母的研究

    Institute of Scientific and Technical Information of China (English)

    陈旭; 王德良; 俞雅琼; 王晓娟; 王志萍; 杨海燕

    2009-01-01

    采用甲基磺酸乙酯(EMS)对啤酒酵母进行化学诱变,利用酸变性血红蛋白平板筛选得到5株低产蛋白酶A的菌株.通过发酵栓试验,测定发酵综合性能,其中突变株E10在发酵力、双乙酰还原能力和风味物质等综合指标保持了亲株的优良性状,同时蛋白酶A活力显著降低,遗传5代,测其发酵性能,表明遗传性状稳定.%Ethyl methane sulphonate (EMS) was used to induce saccharomyces cerevisiae, and obtained 5 mutants, low-yielding procinase A, with acid-denatured acid-denatured hemoglobin plate. All mutants were further screened through repeated fermentations. Some physical properties were measured. The results showed that fermenting power, biacetyl and flavor components of strain E10 were as much as that of the original strain. Its capacity of yielding proteinase A was much lower than that of original strain, and the mutant strain had the hereditary stability.

  11. Avaliação da qualidade de caldo de cana envasado a quente e por sistema asséptico Quality of sugarcane (Sacharum ssp. juice packed by hot fill and aseptic processes

    Directory of Open Access Journals (Sweden)

    Karin Samorano da Silva

    2006-12-01

    Full Text Available Dois processos térmicos foram aplicados ao caldo de cana com o objetivo de se obter um produto estável à temperatura ambiente. A variedade de cana de açúcar (Sacharum ssp. utilizada foi a RB72 - 454. A metodologia de planejamento fatorial foi aplicada a fim de se verificar a melhor combinação entre acidez (pH e doçura (°Brix. Houve uma tendência para melhor aceitação sensorial quando o pH foi maior que 4,0 e °Brix maior que 15. Primeiramente, o caldo foi submetido a 141 °C /10 s e envasado assepticamente em garrafas de vidro previamente esterilizadas. No segundo processo, o caldo foi submetido ao tratamento térmico a 110 °C /10 s e envasado a quente (90 ± 5 °C em garrafas de vidro. Análises físico-químicas, microbiológicas e sensoriais foram realizadas durante a estocagem dos lotes à temperatura ambiente. O lote processado assepticamente apresentou vida útil de 30 dias e o envasado a quente, 60 dias, não apresentando diferença estatística (p The objective of this work is to evaluate two thermal processes in order to obtain sugarcane (Sacharum ssp. juice stable at room temperature in glass bottles. An experimental methodology was applied to obtain the best combination between pH and °Brix based on the sensory results. There was a tendency for a better sensory acceptance for pH > 4.0 and °Brix > 15. Two thermal processes were applied to sterilize the juice. Firstly, the juice was submitted to 141 °C /10 s, and then aseptically filled in glass bottles previously sterilized. In the second process, the juice was submitted to 110 °C /10 s and filled into glass bottles at 90 ± 5 °C. Physical-chemical changes, microbiological counts and sensory acceptance were evaluated during the storage at room temperature. The shelf life of aseptically processed juice was 30 days and 60 days for the hot filled juice based on the sensory evaluation. These results indicated that the hot fill process was more efficient for sugarcane

  12. Emprego do extrato de moringa (Moringa oleífera Lamarck) na clarificação do caldo de cana para produção de açúcar

    OpenAIRE

    Costa, Gustavo Henrique Gravatim [UNESP

    2013-01-01

    Devido a crescente demanda mundial e rigorosas especificações exigidas pelo mercado para o açúcar, as unidades produtoras investem em inovações e tecnologias de produção, afim de reduzir custos e aprimorar a qualidade deste produto. Entre as possíveis inovações industriais, destaca-se o tratamento do caldo. Tal processo visa remover ao máximo os compostos considerados impurezas para a fabricação de açúcar, como compostos fenólicos, proteínas, sais inorgânicos, aminoácidos, ácidos, entre outro...

  13. Isolation and characterization of Saccharomyces cerevisiae strains of winery interest Isolamento e caracterização de cepas de Saccharomyces cerevisiae de interesse em produção de vinho

    Directory of Open Access Journals (Sweden)

    Thais M. Guimarães

    2006-03-01

    Full Text Available Despite the availability of several Saccharomyces cerevisiae commercial strains intended for wine production, strains isolated from winery regions are usually more adapted to their own climatic conditions, grapes and also partially responsible for particular characteristics that frequently identify specific wines and regions. Thus the microbiota of an important winery region (Colombo was studied in order to isolate and characterize S. cerevisiae strains that could be used on wine production. From 61 yeasts isolated, 14 were identified as S. cerevisiae. Some of them showed fermentative characteristics even better than commercial strains indicating that they could be applied on wine production in order to increase the quality and assure the particular wine characteristics of that region.

  14. Acompanhamento do processo de fermentação para produção de cachaça através de métodos microbiológicos e físico-químicos com diferentes isolados de Saccharomyces cerevisiae

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    Thaís Louise Soares

    2011-03-01

    Full Text Available Com a crescente exigência do mercado consumidor por produtos de melhor qualidade, busca-se o constante aprimoramento da produção de cachaça, uma vez que todas as etapas da cadeia produtiva de bebidas fermento-destiladas são importantes. O objetivo deste trabalho foi acompanhar o processo de fermentação para produção de cachaça, utilizando diferentes isolados de Saccharomyces cerevisiae a partir da quantificação de metabólitos secundários por Cromatografia Gasosa. O acompanhamento do processo deu-se desde o preparo do inóculo até o final do processo fermentativo. O estudo foi conduzido na Universidade Federal de Lavras (UFLA. Foram utilizados 8 isolados de Saccharomyces cerevisiae inoculados em caldo de cana, dos quais foram retiradas amostras durante a fase de crescimento em sistema de batelada alimentada e fermentação. As amostras foram analisadas quanto à taxa de floculação, ºBrix e álcoois superiores. Os parâmetros avaliados apresentaram diferenças para cada isolado. O melhor isolado para a produção de cachaça foi o isolado UFLA CA116 por apresentar alto número de células viáveis, maior taxa de floculação, ausência 1-propanol, presença de 1,3 butanediol.

  15. Farinha de mandioca enriquecida com bioproteínas (Saccharomyces cerevisiae, em associação ao feijão e arroz, na dieta de ratos em crescimento Cassava flour enriched with yeast (Saccharomyces cerevisiae protein, in association with beans and rice, in the diet of growing rats

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    Anastácia Cavalcanti Metri

    2003-01-01

    Full Text Available Avaliou-se o efeito da mistura de feijão, arroz e farinha de mandioca enriquecida com bioproteína (Saccharomyces cerevisiae, em ratos wistar machos recém-desmamados (n=60, durante 28 dias. Foram utilizadas as seguintes dietas: experimentais (feijão, arroz e farinha de mandioca enriquecida com leveduras; feijão, arroz e farinha de mandioca comum; controle (farinha de mandioca enriquecida com levedura; e padrão (caseína. Determinaram-se os testes biológicos. Os orgãos foram removidos para análise de pesos úmido e seco (rim esquerdo, baço e amostras do fígado e cérebro, teor de proteína (fígado e cérebro e histopatologia (fígado, coração e rim direito. Foram ainda quantificados os lipídios totais da carcaça dos animais. Os dados foram estatisticamente avaliados pelo teste Não Paramétrico de Kruskal-Wallis e pelo teste de Comparações Múltiplas (pThe effect of a mixture of beans, rice and cassava flour enriched with yeast (Saccharomyces cerevisiae protein was assessed in weanling male Wistar rats (n=60, during 28 days. The following diets were used: experimental (beans, rice and manioc flour with yeast protein; beans, rice and cassava flour without yeast protein; control (cassava flour with yeast protein; and standard (casein. The biological test were determined. The organs were removed for evaluation of wet and dry weights (left kidney, spleen and liver and brain samples, protein levels (liver and brain, and histopathology (heart, right kidney and liver. Carcass total lipids were also recorded. Results were statistically analyzed by the Nonparametric Test of Kruskal-Wallis and the Test of Multiple Comparisons (p<0.05. The highest values for all investigated parameters were found in the casein-fed group, followed by the experimental groups. Data suggest that flour enriched with yeast protein can be recommended as a dietary supplement to eradicate the nutritional deficiency in the poor population.

  16. Cellular viability of Saccharomyces cerevisiae cultivated in association with contaminates bacteria of alcoholic fermentation;Viabilidade celular de Saccharomyces cerevisiae cultivada em associacao com bacterias contaminantes da fermentacao alcoolica

    Energy Technology Data Exchange (ETDEWEB)

    Nobre, Thais de Paula

    2005-07-01

    The aim of this work was to study the influence of the bacteria Bacillus and Lactobacillus, as well as their metabolic products, in reduction of cellular viability of Saccharomyces cerevisiae, when in mixed culture of yeast and active and treated bacteria. Also was to evaluated an alternative medium (MCC) for the cultivation of bacteria and yeast, constituted of sugarcane juice diluted to 5 deg Brix and supplemented with yeast extract and peptone. The bacteria Bacillus subtilis, Bacillus coagulans, Bacillus stearothermophilus, Lactobacillus fermentum and Lactobacillus plantarum were cultivated in association with yeast Saccharomyces cerevisiae (strain Y-904) for 72 h on 32 deg C, under agitation. The cellular viability, budding rate and population of S. cerevisiae, the total acidity, volatile acidity and pH of culture were determined from 0, 24, 48 e 72 h of mixed culture. Also were determined the initial and final of microorganism population across the pour plate method, in traditional culture medium (PCA for Bacillus, MRS-agar for Lactobacillus and YEPD-agar for yeast S. cerevisiae) and in medium constituted of sugarcane juice. The bacteria cultures were treated by heat sterilization (120 deg C for 20 minutes), antibacterial agent (Kamoran HJ in concentration 3,0 ppm) or irradiation (radiation gamma, with doses of 5,0 kGy for Lactobacillus and 15,0 kGy for Bacillus). The results of the present research showed that just the culture mediums more acids (with higher concentrations of total and volatile acidity, and smaller values of pH), contaminated with active bacteria L. fermentum and B. subtilis, caused reduction on yeast cellular viability. Except the bacteria B. subtilis treated with radiation, the others bacteria treated by different procedures (heat, radiation e antibacterial) did not cause reduction on yeast cellular viability and population, indicating that the isolated presence of the cellular metabolic of theses bacteria was not enough to reduce the

  17. Study of clarification process of sugar cane juice for consumption Desenvolvimento de processo de clarificação de caldo de cana para consumo

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    Patricia Prati

    2010-09-01

    Full Text Available Sugar cane juice or garapa darkens quickly after extraction due to the oxidation of some of its constituents harming its commercialization thus requiring rapid consumption. The objective of this study was to develop a mild process for sugar cane clarification, obtaining a cloudy, greenish-yellow beverage. The following parameters were combined to aiming at this objective: heat treatment at 65 ºC/50 minutes; pH change (to 7.0, 7.5, and 8.0; addition of flocculant (0, 30, and 60 ppm Aluminum polychloride or APC - "Panclar P-1010", and clarifier aid (0, 2, or 4 ppm of positively charged polyelectrolyte - "Magnafloc LT-27". The decantation time was 45 minutes and the supernatant liquid was removed with a vacuum pump. The treatments were defined using the Response Surface Methodology and were submitted to physicochemical analysis for turbidity (%, total polysaccharide content (µg.mL-1, dextran content (µg.mL-1, and sensory analysis (acceptance test for the attributes of color, appearance, and turbidity. It was concluded that the addition of 60 ppm APC, pH 8, and 0 ppm polyelectrolyte represented the best treatment to obtain a low polysaccharide content, 90% turbidity, and high scores for color, appearance, and turbidity. The beverage was sensorially well accepted by consumers.A garapa ou caldo de cana, após sua extração, escurece em razão da oxidação de seus constituintes. Este fato prejudica a comercialização da bebida que então deve ser consumida rapidamente. O presente trabalho teve como objetivo desenvolver um processo brando de clarificação do caldo de cana de forma a obter uma garapa turva e de coloração amarelo-esverdeada. Para alcançar este objetivo, associaram-se: aquecimento a 65 ºC/50 minutos; mudança de pH do meio (valores de pH 7,0; 7,5; e 8,0; adição de floculante (0, 30 e 60 ppm de Policloreto de Alumínio ou PAC - "Panclar P-1010"; e auxiliar de clarificação (0, 2 e 4 ppm de polieletrólito negativamente

  18. Monensina sódica e Saccharomyces cerevisiae em dietas para bovinos: fermentação ruminal, digestibilidade dos nutrientes e eficiência de síntese microbiana Sodium monensin and Saccharomyces cerevisiae in cattle diets: ruminal fermentation, nutrient digestibility and microbial synthesis efficiency

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    Fernanda Fereli

    2010-01-01

    Full Text Available Avaliaram-se os efeitos do uso de monensina sódica, Saccharomyces cerevisiae e da mistura de ambos na dieta de bovinos sobre o pH e a concentração de amônia no rúmen, a digestibilidade aparente parcial e total dos nutrientes e a síntese de proteína microbiana no rúmen. Foram utilizados quatro bovinos da raça Holandesa Preto e Branco, castrados, com 320 kg de peso vivo, e canulados no rúmen. O delineamento experimental utilizado foi o quadrado latino 4 × 4, e os tratamentos consistiram de doses diárias de: 200 mg de monensina sódica (100I; 100 mg monensina sódica + 2,5 g Saccharomyces cerevisiae (50IP; 200 mg de monensina sódica + 5 g Saccharomyces cerevisiae (100IP; e 5 g Saccharomyces cerevisiae (100P, fornecidos diariamente pela cânula ruminal. A dieta contendo 100I promoveu menor digestão intestinal e total da matéria seca (MS, maior digestão intestinal da fibra em detergente neutro (FDN e do extrato etéreo (EE, maior digestão total da proteína bruta (PB e do EE e maior coeficiente de digestibilidade aparente ruminal (CDAR e total (CDAT da PB. A dieta contendo 100P resultou em menor digestão ruminal da PB, maior digestão ruminal da FDN, maior digestão intestinal da matéria orgânica (MO, da PB e dos carboidratos não-fibrosos (CNF, maior digestão total da matéria orgânica e do extrato etéreo, maior CDAR da FDN, maior coeficiente de digestibilidade intestinal (CDAI da MO e dos CNF e maior CDAT da MO. A dieta 100P promoveu maior fluxo omasal de nitrogênio bacteriano e maior eficiência microbiana aparente e verdadeira. A dieta com 5 g/dia de Saccharomyces cerevisiae apresentou valor de NDT superior ao das outras dietas. As dietas não diferem quanto ao pH e à concentração de amônia no rúmen.The study was conducted to evaluate effects of sodium monensin, Saccharomyces cerevisiae and a mixture of both, in cattle diets, on ruminal pH and ammonia concentration, partial and total nutrient digestibility, and

  19. Enriquecimiento de agar marino y tcbs con caldos de músculo y hepatopáncreas de camarón penaeus vannamei

    OpenAIRE

    1998-01-01

    Enriquecimiento de agar Marino y TCBS con caldos de músculo y hepatopáncreas de camarón Penaeus vannamei En cultivo de camarón, los monitoreos bacteriológicos se realizan en base al uso de medios de aislamiento originalmente concebidos para bacterias de importancia médica.

  20. Avaliação de ensaios analíticos para detecção de coliformes fecais em queijo Minas

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    Pereira M.L.

    1999-01-01

    Full Text Available Foram submetidas à pesquisa de coliformes fecais, utilizando-se a técnica do número mais provável (NMP/g, 168 amostras de variedades de queijo Minas (20 frescal, 48 canastra e 100 padronizado coletadas em Belo Horizonte. Para a comparação de diferentes ensaios em temperatura elevada, utilizou-se o caldo EC isoladamente, e caldos EC e triptofano em paralelo. Visando à pesquisa de indol foi realizado ensaio para confirmação de produção de beta-D-glucuronidase e indol em caldo fluorocult lauril sulfato. Os resultados demonstraram não haver diferença estatística significativa entre as três metodologias utilizadas para a pesquisa de coliformes fecais, considerando os índices de aceitação definidos pelos padrões legais de inspeção de queijo Minas. A facilidade de execução do ensaio da beta-D-glucuronidase em caldo fluorocult lauril sulfato, associada à confiabilidade dos resultados e demanda de tempo (redução de 96 para até 48h, permitem sugeri-lo como método de escolha para enumeração de coliformes em queijo Minas.

  1. Evaluation of milk production and somatic cell count of dairy cow supplemented with Saccharomyces cerevisiae as a source of organic zinc/ Avaliação da produção de leite e contagem de células somáticas em bovinos leiteiros suplementads com Saccharomyces cerevisiae como fonte de zinco orgânico

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    Adalberto José Crocci

    2007-08-01

    Full Text Available The aim of the evaluation of milk production and somatic cell count of dairy cow supplemented with Saccharomyces cerevisiae as a source of organic zinc for 180 days, 25 Holstein cows were selected, randomly chosen from a flock of 189 lactating cows. The animals were distributed in two groups, namely group 1 (G1 which holded 10 cows supplemented and group 2 (G2 with 15 animals without supplementation. The production of milk was measured by the control official milkman of the Assocition Paranaense of Creators of Bovine of the Holstein in seven moments during the 180 days. The samples of milk were collected of each animal, being submitted to the electronic counting of somatic cells. The results demonstrate that the supplemented of organic zinc didn’t alter the production of milk, however it was capable to maintain low the counting of somatic cells. The data of the present work suggest that to use supplemented of organic zinc in the diet of cows milk, increase the quality of the produced milk and consequently the remuneration for the producer.Com o objetivo de avaliar a produção de leite e a contagem de células somáticas de bovinos leiteiros, suplementados com Saccharomyces cerevisiae, como fonte de zinco orgânico, por 180 dias, foram separadas aleatoriamente 25 vacas holandesas, em um rebanho de 189 vacas em lactação. Os animais foram distribuídos em dois grupos, sendo grupo 1 (G1 composto por 10 vacas suplementadas e grupo 2 (G2 15 animais sem suplementação. A produção de leite foi mensurada pelo controle leiteiro oficial da Associação Paranaense de Criadores de Bovinos da Raça Holandesa em sete momentos durante os 180 dias. As amostras de leite foram coletadas de cada animal, sendo submetidas à contagem eletrônica de células somáticas. Os resultados demonstram que a suplementação de zinco orgânico não alterou a produção de leite, contudo foi capaz de manter baixa a contagem de células somáticas. Os dados do presente

  2. Serum zinc concentration of dairy cow supplemented with Saccharomyces cerevisiae, with and without hoof lesions / Concentração do zinco sérico em vacas leiteiras suplementadas com Saccharomyces cerevisiae, portadoras ou não de lesões podais

    Directory of Open Access Journals (Sweden)

    Luis Carlos Vianna

    2009-07-01

    Full Text Available The present study was conducted to evaluate bovine serum zinc concentration in animals with and without hoof lesions, supplemented or not with Saccharomyces cerevisiae, an organic zinc source. The supplementation was carried out during 180 days. Forty-five Holstein cows were randomly chosen from a dairy herd of 189 lactating cows. The animals were distributed in three groups. In G1, 20 heifers with foot lesions were fed a diet supplemented with S. cerevisae. In G2, 10 heifers without hoof lesions were fed a diet with supplementation. In G3, 15 heifers with hoof lesions were fed a diet without supplementation. Serum samples were collected on day 0, 90 and 180, after the beginning of the experiment. Serum zinc concentration was determined by Atomic Absorption Spectrophotometry. The results showed there not to be an increase significant serum of zinc among the groups, and in the animals inside of the group 1 (G1 it happened an increase (P Com o objetivo de determinar as concentrações de zinco no soro de bovinos com e sem lesões podais, suplementados ou não com Saccharomyces cerevisiae, como fonte de zinco orgânico, por 180 dias, foram selecionadas e examinadas 45 vacas holandesas pretas e brancas, escolhidas aleatoriamente em um rebanho de 189 vacas em lactação. Os animais foram distribuídos em três grupos, sendo grupo 1 (G1 composto por 20 vacas com lesões podais e suplementadas, grupo 2 (G2 10 animais sem lesões e com suplementação, e grupo 3 (G3 15 animais com lesões e sem suplementação. Amostras de soro foram coletadas no momento inicial (dia zero, 90 e 180 dias após início do experimento, sendo as concentrações determinadas por espectrofotometria de absorção atômica. Os resultados demonstram não haver um aumento sérico significativo de zinco entre os grupos, sendo que nos animais dentro do grupo 1 (G1 ocorreu um aumento (P < 0,01 da concentração de zinco (0,84 para 1,16µg/mL. A suplementação oral de zinco org

  3. Fermentação alcoólica do caldo de cana-de-açúcar var. co. 290. IV - Efeito da adição de tiamina e manganês sôbre o rendimento alcoólico On the influence of thiamine and manganese sulfate in the alcoholic fermentation of sugar cane juice var. Co.290

    Directory of Open Access Journals (Sweden)

    C. G. Teixeira

    1957-01-01

    Full Text Available Realizou-se uma experiência comparativa para verificar a influência da adição de tiamina e sulfato de manganês sôbre o rendimento alcoólico obtido pela fermentação do caldo de cana de açúcar da variedade Co. 290. Verificou-se que tanto a tiamina como o sulfato de manganês provocam um aumento no rendimento alcoólico. Pela adição das duas substâncias ao caldo de cana a ser fermentado, obtêm-se rendimentos alcoólicos superiores àquêles resultantes da adição de cada uma delas em separado. Rendimentos alcoólicos mais elevados foram ainda obtidos pela adição de farelo de arroz ao caldo de cana a ser fermentado. O farelo de arroz parece ser altamente benéfico na fermentação alcoólica em virtude do seu teor elevado em tiamina e, talvez, outras substâncias de importância para a nutrição e atividade do fermento alcoólico, tais como o ácido pantotênico e o manganês.Experiments were carried out to evaluate the influence of the addition of thiamine and manganese sulfate in the alcoholic fermentation of the sugar cane juice var. Co. 290. The results showed an activation of the alcoholic fermentation resulting in better alcoholic yields. The addition of the two substances together resulted in better yields than those obtained from fermenting juices enriched with only one of them. Still better yields were obtained by the enrichment of the sugar cane juice with rice polishings. Rice polishings seem to be active because of their high content in thiamine and/or perhaps by the presence of other substances which are useful for the yeast nutrition and activity such as pantothenic acid and manganese.

  4. Influência de frações da parede celular de levedura (Saccharomyces cerevisiae sobre alguns parâmetros nutricionais de ratos em crescimento Influence of yeast (Saccharomyces cerevisiae cell wall fractions on some nutritional parameters of growing rats

    Directory of Open Access Journals (Sweden)

    Saula Goulart Chaud

    2008-04-01

    Full Text Available OBJETIVO: O objetivo deste trabalho foi avaliar a influência das frações de parede celular de levedura (Saccharomyces cerevisiae sobre alguns parâmetros nutricionais de ratos Wistar em crescimento. MÉTODOS: A biomassa de levedura (Saccharomyces cerevisiae, coletada sem sofrer o processo de termólise, foi recebida da usina São José, Zillo Lorenzetti (Macatuba, SP, em suspensão de, aproximadamente, (20% p/v de células. O fracionamento da parede celular da levedura foi realizado por extração diferencial, centrifugação e secagem em spray dryer. A importância como fibra da dieta foi determinada em ratos da linhagem Wistar, recém desmamados, por meio das seguintes avaliações: ganho de peso corporal, consumo de dieta (28 dias, quociente de eficiência da dieta, digestibilidade aparente da proteína, quantidade total de fezes, lipídeos e colesterol excretados nas fezes. RESULTADOS: Os animais que receberam a dieta contendo a fração glicana mais manana ganharam menos peso em relação aos demais tratamentos. A dieta com a fração manana foi a que proporcionou maior ganho de peso, seguida pela dieta padrão (AIN-P e a dieta com 10% de glicana insolúvel. Quanto ao quociente de eficiência da dieta, observou-se, ao longo dos 28 dias, que a dieta com a fração glicana mais manana foi a que apresentou os menores valores. As maiores porcentagens de digestibilidade aparente da proteína foram observadas nas dietas: padrão modificada (AIN-M, padrão (AIN-P e (M com 10% da fração manana. As quantidades de lipídeos totais e colesterol excretados nas fezes variaram bastante entre as dietas, sendo que a dieta formulada com 10% de fração manana foi a que promoveu maior excreção do colesterol. CONCLUSÃO: Ao final de 28 dias, os animais que receberam a dieta contendo 10,0% da fração glicana mais manana apresentaram o menor consumo de dieta e ganharam menos peso em relação às demais dietas. A digestibilidade aparente de todas as

  5. Composição química de tabletes de caldo de carne: nitrogênio protéico, não-protéico e fenilalanina

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    Guimarães Claudia Passos

    2002-01-01

    Full Text Available A redução dos níveis sangüíneos de fenilalanina (Phe em pacientes fenilcetonúricos requer o conhecimento preciso do teor de Phe nos alimentos, para que possa haver um controle da ingestão desse aminoácido. Este trabalho teve como objetivo estudar o teor protéico e de Phe em tabletes de caldo de carne de duas marcas comerciais, contribuindo com informações para a elaboração de cardápios. A análise de aminoácidos foi realizada por cromatografia de troca iônica em autoanalisador de aminoácidos e os teores de umidade, proteína bruta (Nx6,25 e lipídeos foram determinados por métodos descritos na AOAC (1995. A fibra alimentar foi quantificada por método enzimático. O nitrogênio protéico (NP foi determinado após precipitação ácida da proteína. Observamos que os teores de umidade, lipídeos foram semelhantes nos dois produtos com valores médios de 3,7%, e 8,4%, respectivamente. Os teores de fibra foram inferiores a 2%, mas vale ressaltar o elevado teor de minerais, da ordem de 61% no produto A e de 54% no produto B. Comparando-se os valores de nitrogênio total e NP, verificamos que aproximadamente 95% do N correspondem a N de origem não protéica. O teor protéico real, pela somatória de aminoácidos, era de apenas 0,71g/100g e de 0,84g/100g nas amostras A e B, respectivamente, e não foi possível detectar a presença de Phe nestas amostras. Teoricamente, considerando que uma proteína contém 4% de Phe em sua composição, as amostras analisadas contém no máximo 34mg Phe/100g, o que corresponde a 3,6mg Phe por tablete de caldo de carne de 10,5g. Esta reduzida quantidade justifica a dificuldade em se detectar analiticamente este aminoácido. A elevada quantidade de nitrogênio não protéico corresponde à presença de monoglutamato de sódio (realçador de sabor, de modo que a conversão Nx6,25 resulta em valores protéicos superestimados.

  6. Ventajas Del Perenox. Fungicida de la Casa COOPER sobre el Caldo Bordelés y otros productos a base de cobre.

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    Universidad Nacional de Colombia Facultad de Ciencias Agrarias

    1941-10-01

    Full Text Available "Perenox" es un Oxido de Cobre especialmente preparado, presentado en la forma de un polvo dispersivo extraordinariamente soluble en agua. Contiene 50 % de Cobre, mientras que los cristales del Sulfato de Cobre sólo contienen 25%, Una libra de "Perenox" reemplaza a lo menos 4 libras de Sulfato de Cobre y la correspondiente cantidad de cal y adherentes necesarios para la preparación del Caldo Bordelés. El "Perenox" se puede usar en todos esos casos en que entra el empleo del Caldo Bordelés, como por ejemplo para fumigar contra la "Gota" de la papa, la "Sigatoka" del banano, enfermedades de los cafetos, árboles de cacao, árboles frutales, etc. Se puede agregar al "Perenox" arseniato de plomo u otras substancias cuando se desee también controlar plagas de insectos.

  7. Production and characterization of glucoamylase from fungus Aspergillus awamori expressed in yeast Saccharomyces cerevisiae using different carbon sources Produção e caracterização da glucoamilase do fungo Aspergillus awamori expressa em levedura Saccharomyces cerevisiae usando diferentes fontes de carbono

    Directory of Open Access Journals (Sweden)

    Fabiana Carina Pavezzi

    2008-03-01

    Full Text Available Glucoamylase is widely used in the food industry to produce high glucose syrup, and also in fermentation processes for production beer and ethanol. In this work the productivity of the glucoamylase of Aspergillus awamori expressed by the yeast Saccharomyces cerevisiae, produced in submerged fermentation using different starches, was evaluated and characterized physico-chemically. The enzyme presented high specific activity, 13.8 U/mgprotein or 2.9 U/mgbiomass, after 48 h of fermentation using soluble starch as substrate. Glucoamylase presented optimum activity at temperature of 55ºC, and, in the substratum absence, the thermostability was for 1h at 50ºC. The optimum pH of activity was pH 3.5 - 4.0 and the pH stability between 5.0 and 7.0. The half life at 65ºC was at 30.2 min, and the thermal energy of denaturation was 234.3 KJ mol-1. The hydrolysis of different substrate showed the enzyme's preference for the substrate with a larger polymerization degree. The gelatinized corn starch was the substratum most susceptible to the enzymatic action.A glucoamilase é amplamente utilizada na indústria de alimentos no processamento do amido para a produção de xarope com alto teor de glicose e também muito empregada nos processos de fermentação para produção de cerveja e etanol. Neste trabalho a glucoamilase de Aspergillus awamori expressa em Saccharomyces cerevisiae produzida sob fermentação líquida foi avaliada quanto à produtividade em diferentes amidos e caracterizada físico-quimicamente. A enzima apresentou alta atividade específica de 13,8 U/mg proteína e de 2,9 U/mg biomassa ao final de 48 h de fermentação em meio contendo amido solúvel. A glucoamilase apresentou temperatura ótima de atividade a 55ºC, e temperatura de desnaturação térmica na ausência de substrato por 1h a 50ºC. O pH ótimo de atividade foi na faixa de 3,5 - 4,0 e a estabilidade ao pH entre os valores 5,0 e 7,0. A meia vida a 65ºC foi 30,2 min., e a

  8. DETERMINATION OF AMINO ACIDS COMPOSITION IN MOLASSES YEAST (Saccharomyces cerevisiae AND FISH MEAL PROTEIN AS INGREDIENTS FOR FRESHWATER FISH RATIONS DETERMINAÇÃO DA COMPOSIÇÃO EM AMINOÁCIDOS DAS PROTEÍNAS DA LEVEDURA DE ÁLCOOL (Saccharomyces cerevisiae SECA E DA FARINHA DE PEIXE COMO INGREDIENTES PARA RAÇÕES DE PEIXES DE ÁGUA DOCE

    Directory of Open Access Journals (Sweden)

    Delma Machado Cantisani Pádua

    2007-09-01

    Full Text Available

    The possible use of microbial biomass to replace part of the fishmeal in fish diets could be considered an innovate solution. A quantitative determination of the content of aminoacids was made in two protein sources: molasses yeast (<em>S. cerevisiae> and fish meal. The chemical score and essential aminoacid index were calculated as a parameter correlated to biological value. The high lysine, threonine and tryptophan content of the protein in the molasses yeast must be emphasized. It reaches an order of magnitude superior to that in fish meal. Further researches, especially in relation to protein digestibility and possible toxicity or antinutritional components in the molasses yeast, are certainly a warranty to access the nutritive value of yeast product for fresh water fishes before the acceptable dietary level of these products can be recommended.

    KEY-WORDS: Molasses yeast; protein; fish; diets.

    Determinaram-se a composição e a qualidade protéica da levedura seca de destilaria alcoólica (<em>S. cerevisiae>, comparando-a com a farinha de peixe (FP. Utilizaram-se o escore químico (EQ e o índice de aminoácidos essenciais (IAAE. Estes quocientes indicam, em relação à proteína do ovo, a ordem dos aminoácidos limitantes, estimando assim o valor biológico protéico. Observaram-se elevados índices de lisina (EQ = 120, treonina (EQ = 110 e triptofano (EQ = 100 na levedura, recomendando-se seu balanceamento com cereais deficientes nestes aminoácidos. A proteína da levedura superou a da FP nestes índices de qualidade e satisfez o padrão internacional de qualidade e as exigências em aminoácidos estimados para a carpa e o pacu. Posteriores ensaios acerca de desempenho produtivo, de digestibilidade e de efeitos metabólicos com peixes fornecerão importantes

  9. Purificación parcial del Pioverdin a partir de caldos de fermentación de Pseudomonas aeruginosa PSS

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    Daniel Bello

    2006-01-01

    Full Text Available Se establece un protocolo para la purificación parcial del sideróforo pioverdin a partir de caldos de fermentación de Pseudomonas aeruginosa PSS. La purificación del sideróforo pioverdin se llevó a cabo en dos etapas: aislamiento del complejo sideróforo-Fe(III por extracción con solventes orgánicos y purificación por cromatografía de intercambio iónico. El estudio del espectro de absorción en el uv/vis se realizó a tres pH diferentes: 3, 7 y 8, el rango de longitud de onda ensayado comprendió desde 300-800 nm. Las fracciones con mayor grado de pureza fueron analizadas por HPLC, desacomplejadas con la 8- hidroxiquinolina y ensayadas sus potencialidades antimicrobianas frente al hongo Alternaria alternata. La fracción 1 desacomplejada produjo una inhibición total del crecimiento micelial de Alternaria alternata y mostró espectros característicos que confirmaron la presencia del pioverdin en esta fracción.

  10. Addition of proteic nitrogen during alcoholic fermentation for the production of cachaça Adição de nitrogênio protéico durante a fermentação alcoólica de caldo de cana para produção de cachaça

    Directory of Open Access Journals (Sweden)

    Elisangela Marques Jeronimo

    2008-04-01

    Full Text Available Cachaça is the denomination of a typical and exclusive Brazilian spirit produced from the distillation of fermented sugarcane juice must. The objective of this study was to evaluate the effect of adding yeast extract to the sugarcane juice used for sugarcane liquor production, because for the artisanal process no studies are available on nitrogen addition nor beverage quality, involving nitrogen complementation. Results of previous studies in the laboratory scale showed that sugarcane juice complementation with proteic nitrogen can be a beneficial practice for yeast multiplication and cellular growth, and also for the improvement of fermentation yield and liquor productivity. In this pilot scale study, using recycled yeast, the addition of proteic nitrogen influenced positively the cell viability, confirmed the yeast recycling operation, and also reduced the fermentation time. The proteic nitrogen addition did not affect the sensory acceptance of the distillate, and did not change the contents of volatile compounds, indicating that assimilable forms of proteic nitrogen can be helpfull to improve the alcoholic fermentation for cachaça production.Cachaça é a denominação de uma típica e exclusiva bebida destilada brasileira produzida a partir da destilação do caldo fermentado da cana-de-açúcar. O objetivo deste estudo foi avaliar a adição de extrato de levedura no mosto de caldo de cana para a produção de cachaça, pois em processo artesanal não há estudos específicos sobre as características fermentativas da levedura assim como sobre a qualidade da bebida, envolvendo a complementação nitrogenada e em específico a aplicação de nitrogênio protéico. Os resultados obtidos em trabalhos anteriores, conduzidos em laboratório, indicaram que nas destilarias artesanais de aguardente a complementação protéica do mosto pode constituir uma prática benéfica para a multiplicação e crescimento celular do fermento e conseq

  11. Ethanolic fermentation of sucrose, sugarcane juice and molasses by Escherichia coli strain ko11 and Klebsiella oxytoca strain P2 Fermentação etanólica de sacarose, caldo de cana-de-açúcar e de melaço por Escherichia coli KO11 e Klebsiella oxytoca P2

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    Gervásio P. da Silva

    2005-12-01

    .As bactérias recombinantes Escherichia coli KO11 e Klebsiella oxytoca P2 fermentaram sacarose a etanol. Em meio mínimo com 2% ou 12% de sacarose, KO11 apresentou, respectivamente, 75% e 41% do rendimento máximo teórico (0,54g de etanol/g de sacarose. No caldo Luria-Bertani (LB com até 8% de sacarose, KO11 apresentou rendimento de aproximadamente 94-96% e com 12% de sacarose, KO11 apresentou cerca de 69% de rendimento (44,5g de etanol/L. A porcentagem do rendimento máximo teórico obtida com P2 em meio mínimo com 2% de sacarose foi de 55% e com 12% de sacarose foi de 47%. Em LB com 2 ou 4% de sacarose, P2 apresentou 94-95% do rendimento máximo teórico, porém somente cerca de 73% com 8% de sacarose (31,4g de etanol/L e 58% com 12% de sacarose (37,5 g/L. A produtividade volumétrica em LB contendo 2% de sacarose foi de 0,41 g/L/h para KO11 e de 1,1 g/L/h para P2, enquanto que em LB com 12% de sacarose, a produtividade foi 0,96 g/L/h (KO11 e 1,4 g/L/h (P2. Durante a fermentação do caldo de cana, E. coli KO11 e K. oxytoca P2 produziram, respectivamente, 39,4 g de etanol/L e 42,1 g/L quando suplementado com 0,5% de extrato de levedura, micronutrientes e tiamina. No caldo de cana suplementado com os reagentes do meio LB, KO11 apresentou forte inibição da fermentação alcoólica, produzindo apenas 23,0 g de etanol/L, enquanto que P2 produziu 44,2 g/L. A produção de etanol por KO11 e P2, no caldo de cana suplementado com a 0,2% de sulfato de amônio foi, respectivamente: 25,3 e 30,2 g/L, b com sulfato de amônio e micronutrientes: 24,9 e 31,6 g/L, c com sulfato de amônio, micronutrientes e tiamina: 25,6 e 37,5 g/L. Durante a fermentação do melaço, E. coli KO11 apresentou baixa produção de etanol e alta produção de ácido láctico. K. oxytoca P2 produziu 25 g de etanol/L a partir de melaço diluído 10X em água, com ou sem adição de 0,5% de extrato de levedura e 27,8 g/L com reagentes do caldo LB após 96h. P2 produziu 24,5, 26,9, e 28,0 g de etanol/L em

  12. Evaluación de caldo super cuatro y agroplux en el control de Peronospora destructor en cebolla de bulbo

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    Jorge Daniel Rodríguez-Lagos

    2011-02-01

    Full Text Available El cultivo de cebolla de bulbo es muy importante en  la  economía  de muchos  agricultores  de Boyacá  y  otros  departamentos  del  país;  sin embargo, es afectado por varias enfermedades, entre  las  cuales  se destaca  el mildeo  velloso, como  una  enfermedad  que  causa  grandes pérdidas  económicas  por  sus  efectos devastadores; además, la dependencia exclusiva del control químico, hace que la contaminación ambiental y los costos de producción aumenten. Por  esta  razón,  se  evaluaron  10  tratamientos consistentes en cuatro concentraciones de caldo super cuatro  (5%, 10%, 20% ý 30% de CS4 y cuatro de Agroplux  (5%, 10%, 15% ý 20% de Ap, un  testigo químico (metalaxil+mancozeb y uno absoluto, cada uno con tres repeticiones, para un total de 30 unidades experimentales de 9 m2,  donde  fueron  sembradas  plántulas  de cebolla Yellow granex, con un diseño en bloques al  azar.  Las  aplicaciones  se  hicieron decenalmente  y  con  esta misma  frecuencia fueron medidas  la  incidencia y severidad de  la enfermedad. Se registró  la  temperatura, humedad relativa  y  precipitación;  en  la  cosecha  se determinó el  rendimiento y se hizo un análisis económico. Al final, la incidencia fue del 100% y  la  severidad  no  presentó  diferencias estadísticas, pero  fue menor  con  el químico  y los tratamientos de Ap. Con la aplicación de CS4 al  20%  se obtuvo mayor  producción,  ingreso neto y rentabilidad. Además, el desarrollo de la enfermedad  dependió  directamente  de  la precipitación  y  se  pudo  concluir  que  los biopreparados  tienen potencial para el control del mildeo velloso y aumento de la rentabilidad del cultivo de cebolla de bulbo.

  13. 21 CFR 866.5785 - Anti-Saccharomyces cerevisiae (S. cerevisiae) antibody (ASCA) test systems.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Anti-Saccharomyces cerevisiae (S. cerevisiae... Immunological Test Systems § 866.5785 Anti-Saccharomyces cerevisiae (S. cerevisiae) antibody (ASCA) test systems. (a) Identification. The Anti-Saccharomyces cerevisiae (S. cerevisiae) antibody (ASCA) test system...

  14. Vibrio parahaemolyticus produtores de urease isolados a partir de ostras (Crassostrea rizophorae) coletadas in natura em restaurantes e mexilhões (Perna perna) de banco natural

    OpenAIRE

    2004-01-01

    A presença de Vibrio parahaemolyticus foi avaliada em 50 amostras de moluscos bivalves marinhos compostas por 40 amostras de ostras coletadas em 15 restaurantes do Rio de Janeiro e 10 amostras de mexilhões capturados de banco natural em Ponta de Itaipú - Niterói. Foram empregadas a técnica do Número Mais Provável (NMP) para a enumeração de V. parahaemolyticus utilizando Caldo Glicosado Salgado com Teepol (GSTB) e Água Peptonada Alcalina (APA) com 3% de cloreto de sódio (NaCl). Paralelamente f...

  15. Comparison between two selected Saccharomyces cerevisiae strains as fermentation starters in the production of traditional cachaça

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    Fátima de Cássia Oliveira Gomes

    2009-04-01

    Full Text Available Two Saccharomyces cerevisiae strains were tested as the starter yeasts in a traditional cachaça distillery. The strains used were S. cerevisiae UFMG-A829, isolated from a cachaça fermentation process, and S. cerevisiae K1-V1116, obtained from the wine industry. The permanence of each strain in the fermentation must was determined by RAPD (Random Amplified Polymorphic DNA-PCR, with primer M13. Both yeast strains were prevalent in the vats for approximately 30 days. Indigenous non-Saccharomyces and indigenous S. cerevisiae strains were isolated in lower counts during the fermentation period. Indigenous S. cerevisiae strains were molecularly distinct when compared to the starter yeasts. The two yeasts appeared promising starter yeasts in the fermentation process to produce traditional cachaça.Duas linhagens de Saccharomyces cerevisiae foram testadas como iniciadoras em uma destilaria de cachaça. Foram utilizadas as linhagens de S. cerevisiae UFMG-A829, isolada de fermentação de cachaça, e S. cerevisiae K1-V1116, de origem vinícola. A permanência de cada linhagem durante a fermentação foi determinada por RAPD (Random Amplified Polymorphic DNA-PCR, utilizando o iniciador M13. As duas linhagens predominaram nas dornas de fermentação por aproximadamente 30 dias. Leveduras não-Saccharomyces e S. cerevisiae indígenas foram isoladas em menor proporção durante o experimento. As linhagens de S. cerevisiae indígenas apresentaram perfis moleculares distintos em relação às linhagens iniciadoras. As duas linhagens foram promissoras para serem utilizadas como iniciadoras do processo fermentativo para a produção da cachaça.

  16. Efectividad del Caldo Lactosado con Azul de Bromotimol en el control bacteriológico de las desinfecciones profilácticas en instalaciones bovinas

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    Cepero Rodríguez, Omelio:

    2008-09-01

    Full Text Available Con la finalidad de evaluar la efectividad del medio de cultivo CaldoLactosado con Azul de Bromotimol (CLAB en el control bacteriológico de las desinfecciones profilácticas se realizó un estudio en unidades bovinas cuyos resultados se compararon en paralelo con los obtenidos con el medio de Heifetz Modificado (HM, establecido en Cuba para esta actividad. Previa limpieza mecánica se aplicaron las soluciones desinfectantes mediante una unidad móvil y después de tres horas de exposición se realizó el muestreo mediante hisopaje de pisos, comederos, bebederos y paredes, procediéndose posteriormente a la inoculación en los medios de cultivos. La lectura de los resultados se realizó transcurridas 8, 12 y 18 horas de incubación a 37 °C, posteriormente se evaluaron estadísticamente según un análisis de varianza de clasificación simple. En las condiciones del estudio se constató la efectividad CLAB y el HM para el control bacteriológico de las desinfecciones profilácticas en unidades pecuarias, sin diferencias estadísticamente significativas, aunque existen ventajas favorables al CLAB relacionadas con su menor complejidad y frecuencia de contaminación que indudablemente repercuten en un menor costo.

  17. Modificación del caldo extracto de levadura manitol para la producción a mediana escala de inoculantes para leguminosas

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    Ernesto Ormeño-Orrillo

    2014-06-01

    Full Text Available El caldo extracto de levadura manitol (LM, un medio ampliamente utilizado para el cultivo de rizobios, fue modificado para reducir su costo y utilizarlo en la producción a mediana escala de inoculantes para leguminosas. Los dos ingredientes más costosos, el extracto de levadura y el manitol, fueron reducidos o reemplazados con substratos más económicos. Se pudo reducir la concentración de extracto de levadura a 0,05 g/L sin afectar el crecimiento cuando se agregó 1,1 g/L de ácido glutámico o glutamato de sodio grado alimento. El manitol pudo ser substituido por 12,5 g/L de glicerina grado farmacéutico para las cepas de Bradyrhizobium o por 10 g/L de azúcar grado alimento para las cepas de Rhizobium. No se alteraron las propiedades simbióticas de las cepas cultivados en los medios modificados.

  18. AVALIAÇÃO DOS MÉTODOS DE ETEST E MICRODILUIÇÃO EM CALDO PARA O ESTUDO DA SUSCETIBILIDADE DO Sporothrix schenckii COM O ITRACONAZOL

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    Ana Raquel Mano Meinerz

    2010-06-01

    Full Text Available The frequent occurrence of resistant isolated fungi againstantifungal drugs stimulated advances in the antifungigram techniques,which were standardized by CLSI. However, the methods have been inefficient and impractical to be executed in clinical laboratories. Within this context, commercial techniques have been developed, being ETEST one of them. ETEST has proved to be easier to execute when compared to the techniques approved by the CLSI. This study used the ETEST and the microdilution method, performed according to CLSI, for determining the in vitro susceptibility of isolates of Sporothrix schenckii against itraconazole. The CLSI uses RPMI 1640 medium and the reading of MIC after the period of incubation of 72h at 35ºC. MIC was determined by the ETEST, being Sabouraud dextrose agar used as medium, and the reading performed after 72 hours of incubation at 35ºC. The variance analysis, analyzed by T-paired test, did not demonstrate statistical differences among the CIM values obtained by the microdilution technique in broth (MIC among 0.219 and 0.875 μg/mL and ETEST (MIC among 0.032 and 2.0 μg/mL. However, the correlation coefficient (R was negative, probably because ofthe small number of samples. These results show the necessity offurther studies to assess the application of ETEST to evaluate thesusceptibility of S. schenckii against the itraconazol.

  19. Evaluation of cytochrome P-450 concentration in Saccharomyces cerevisiae strains

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    Míriam Cristina Sakuragui Matuo

    2010-09-01

    Full Text Available Saccharomyces cerevisiae has been widely used in mutagenicity tests due to the presence of a cytochrome P-450 system, capable of metabolizing promutagens to active mutagens. There are a large number of S. cerevisiae strains with varying abilities to produce cytochrome P-450. However, strain selection and ideal cultivation conditions are not well defined. We compared cytochrome P-450 levels in four different S. cerevisiae strains and evaluated the cultivation conditions necessary to obtain the highest levels. The amount of cytochrome P-450 produced by each strain varied, as did the incubation time needed to reach the maximum level. The highest cytochrome P-450 concentrations were found in media containing fermentable sugars. The NCYC 240 strain produced the highest level of cytochrome P-450 when grown in the presence of 20 % (w/v glucose. The addition of ethanol to the media also increased cytochrome P-450 synthesis in this strain. These results indicate cultivation conditions must be specific and well-established for the strain selected in order to assure high cytochrome P-450 levels and reliable mutagenicity results.Linhagens de Saccharomyces cerevisiae tem sido amplamente empregadas em testes de mutagenicidade devido à presença de um sistema citocromo P-450 capaz de metabolizar substâncias pró-mutagênicas à sua forma ativa. Devido à grande variedade de linhagens de S. cerevisiae com diferentes capacidades de produção de citocromo P-450, torna-se necessária a seleção de cepas, bem como a definição das condições ideais de cultivo. Neste trabalho, foram comparados os níveis de citocromo P-450 em quatro diferentes linhagens de S. cerevisiae e avaliadas as condições de cultivo necessárias para obtenção de altas concentrações deste sistema enzimático. O maior nível enzimático foi encontrado na linhagem NCYC 240 em presença de 20 % de glicose (p/v. A adição de etanol ao meio de cultura também produziu um aumento na s

  20. Pré-concentração de cádmio com Saccharomyces cerevisiae e determinação em águas fluviais usando espectrometria de emissão óptica com plasma indutivamente acoplado Preconcentration of cadmium with Saccharomyces cerevisiae and determination in river water using inductively coupled plasma optical emission spectrometry

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    Priscila Andreoli Biscaro

    2007-04-01

    Full Text Available A preconcentration method based on the use of Saccharomyces cerevisiae as sorbent material is proposed for the determination of Cd(II in river water. The solid phase extraction was performed in batch mode and the determination of the analyte in the solid phase was easily carried out by introducing a slurry of the yeast (0.0625 g / 2.5 mL directly into the ICP OES. A limit of detection of 0.11 µg L-1 and a sample throughput in the range of 4 - 54 sample h-1 were obtained. Determinations of cadmium in a certified sample and in real river water samples were in excellent agreement with the expected values.

  1. Artigos esterilizados em calor úmido: validação do sistema de guarda

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    Zilah Cândida Pereira das Neves

    2004-04-01

    Full Text Available Objetivamos identificar o tempo de validade da esterilização dos artigos processados pelo calor úmido, considerando as condições de esterilização e guarda. A validação deu-se através de testes microbiológicos realizados com instrumentais processados numa mesma carga e avaliados em tempos 0, 7, 10, 15 e 25 dias. Foram analisados 30% do instrumental de cada pacote que foi colocado em caldo Mueller Hinton e incubado a 37ºC por 72 horas. A leitura deu-se pela turvação do caldo. Das amostras avaliadas de nove cargas, em nenhuma houve crescimento microbiológico. Concluiu-se que apesar das condições de esterilização e guarda do material não se adequarem totalmente dentro dos parâmetros recomendados pela literatura, a esterilização ocorreu e manteve-se por um período de 25 dias.

  2. Efeito do cloreto de sódio na produção de proteínas (Saccharomyces cerevisiae em fermentação semi-sólida Effect of sodium chloride on protein production (Saccharomyces cerevisae by semi-solid fermentation

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    Ana Maria RODRIGUES

    2001-01-01

    Full Text Available Estudou-se o efeito do cloreto de sódio sobre a produção de biomassa e proteínas extracelulares totais, durante o cultivo de Saccharomyces cerevisiae. A levedura foi desenvonvida em fermentador de leito fluidizado, com vazão de ar de 70L/min, temperatura de 33° C, e umidade relativa de 99-100%. Foi utilizado substrato semi-sólido de batatas, previamente hidrolizado, acrescido de cloreto de sódio 0,6M. O crescimento celular foi monitorado por densidade óptica à 595 nm. Observou-se, como resultado, que a adição de cloreto de sódio 0,6M induziu um aumento de 36,86% na produção de proteínas extracelulares totais, mas inibiu o crescimento celular em 27,62% quando os meios com e sem cloreto de sódio foram testados. A produção máxima de biomassa, tanto para os experimentos com adição de cloreto de sódio quanto para o sem adição, ocorreu no período de 7 a 9 horas de fermentacão, enquanto que a produção de proteínas extracelulares totais, independentemente da adição do sal, ocorreu durante o período de 9 a 12 horas de fermentação. As velocidades específicas máximas de crescimento foram de 0,350/h para os experimentos com sal, e de 0,339/h para aqueles sem a adição do sal. A combinação de alta vazão de ar e a presença de cloreto de sódio 0,6M na fermentação parece não ter tido efeito sobre a duração da fase lag na curva de crescimento celular de Saccharomyces cerevisiae.The effect of sodium chloride on the cell's growth and total extracellular protein production during fermentation of Saccharomyces cerevisiae in an air-fluidized bed fermentation, with a 70 L/min air flow at 33° C and 99-100% relative unidity was studied. A semi-solid potato substrate (previously hydrolized with 0.6M sodium chloride was used. Cell's growth was monitored by optical density at 595 nm. Results showed that the addition of 0.6M sodium chloride enhanced total extracellular protein level (36.86%. On the other hand, the addition of

  3. levadura Saccharomyces Cerevisiae

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    B. Aguilar Uscanga

    2005-01-01

    Full Text Available La pared celular de levaduras representa entre 20 a 30 % de la célula en peso seco. Está compuesta de polisacáridos complejos de β-glucanos, manoproteínas y quitina. Se estudió la composición de los polisacáridos contenidos en la pared celular de la Saccharomyces cerevisiae CEN.PK 113 y se observó el efecto de la variación de la fuente carbono (glucosa, sacarosa, galactosa, maltosa, manosa, etanol y pH (3, 4, 5, 6 en un medio mineral “cell factory”. Las células fueron recolectadas en fase exponencial y se extrajo la pared celular. Los extractos de pared se hidrolizaron con H2SO4 al 72% y las muestras fueron analizadas por cromatografía HPLC. Se realizó una prueba de resistencia al rompimiento celular con una β(1,3-glucanasa, y las células cultivadas a diferentes fuentes carbono y pH. Los resultados del análisis por HPLC, mostraron que la composición de los polisacáridos en la pared celular, varía considerablemente con las modificaciones del medio de cultivo. Se observó que las levaduras cultivadas en sacarosa tienen mayor porcentaje de pared celular (25% y mayor cantidad de glucanos (115µg/mg peso seco y mananos (131µg/mg peso seco, que aquellas levaduras cultivadas en etanol (13% en peso seco. Las levaduras cultivadas a pH 5 presentaron 19% de pared celular en peso seco, mientras que a pH 6 el porcentaje fue menor (14%. El análisis de resistencia al rompimiento celular, mostró que las células cultivadas en etanol y galactosa fueron resistentes al rompimiento enzimático. Se comparó este resultado con el contenido de polisacáridos en la pared celular y concluimos que la resistencia de la célula al rompimiento, no está ligada con la cantidad de β-glucanos contenidos en la pared celular, sino que va a depender del número de enlaces β(1,3 y β(1,6-glucanos, los cuales juegan un rol importante durante el ensamblaje de la pared

  4. Proteomics of Saccharomyces cerevisiae Organelles

    NARCIS (Netherlands)

    Wiederhold, Elena; Veenhoff, Liesbeth M.; Poolman, Bert; Slotboom, Dirk Jan

    2010-01-01

    Knowledge of the subcellular localization of proteins is indispensable to understand their physiological roles. In the past decade, 18 studies have been performed to analyze the protein content of isolated organelles from Saccharomyces cerevisiae. Here, we integrate the data sets and compare them wi

  5. Efeitos de dietas contendo Leucaena leucocephala e Saccharomyces cerevisiae sobre a fermentação ruminal e a emissão de gás metano em bovinos Effects of leucaena and yeast on rumen fermentation and methane emissions in cattle

    Directory of Open Access Journals (Sweden)

    Rosana Aparecida Possenti

    2008-08-01

    Full Text Available Este trabalho foi realizado com o objetivo de avaliar os efeitos do uso de leucena e levedura em dietas para bovinos sobre o metabolismo ruminal, incluindo o pH e as produções de ácido graxos voláteis (AGV, amônia e gás metano. Quatro bovinos machos com 800 kg e fistulados no rúmen foram mantidos em quadrado latino 4 × 4, em arranjo fatorial 2 × 2, composto de dois níveis de leucena (20 e 50% MS e feno de capim coast-cross na presença ou ausência de levedura. Não houve influência das dietas nos valores médios de pH (média 6,82 e nas concentrações de amônia no rúmen, que variaram de 18 a 21 mg/100 mL. Houve interação entre níveis de leucena e levedura na concentração total de AGV. As dietas não diferiram quanto à concentração de ácido acético, mas os animais alimentados com a dieta com 50% de leucena e contendo levedura apresentaram maiores concentrações médias de ácido propiônico (média 19,14 mM. A emissão de metano reduziu em12,3% em relação à mesma dieta sem levedura e em 17,2% quando os animais foram alimentados com 20% de leucena com levedura. Verificou-se efeito associativo de leucena, quando fornecida em alto nível na dieta (50% MS, e levedura na redução da emissão de metano e na melhoria no padrão de fermentação no rúmen, o que pode reduzir as perdas de energia e melhorar eficiência energética do animal.This research was to evaluate the effect of Leucaena (Leucaena leucocephala and yeast (Saccharomyces cerevisiae in diets for bovines on ruminal metabolism, including pH, volatile fatty acids, and ammonia and methane production. Four crossbred male cattle (800 kg LW rumen cannulated were distributed to a 4 × 4 Latin Square design, in 2 × 2 factorial arrangement, composed by two levels of Leucaena (20% and 50% DM and coast-cross grass hay, with or without yeast. No differences were observed in rumen pH (mean 6.82 and ammonia concentrations that varied from 18.71 to 21.28 mg/100 mL of

  6. Microbiological and physicochemical evaluations of juice extracted from different parts of sugar cane stalks from three varieties cultivated under organic management Avaliações microbiológicas e físico-químicas do caldo extraído de diferentes partes do colmo de cana-de-açúcar de três variedades cultivadas sob manejo orgânico

    Directory of Open Access Journals (Sweden)

    Cristina Martini

    2010-09-01

    , tradicionalmente utiliza o fermento caipira, o qual consiste de caldo de cana misturado com milho moído, farelo de arroz e sucos de frutas cítricas. Apesar dos inconvenientes como dificuldades no controle de qualidade devido ao alto nível de contaminantes e longos períodos de preparação, a qualidade sensorial da bebida pode ser atribuída às atividades fisiológicas de leveduras selvagens e mesmo bactérias presentes durante a fermentação, quando este tipo de fermento é utilizado. Neste contexto, o objetivo deste trabalho foi avaliar as características microbiológicas (leveduras e físico-químicas do caldo de cana extraído de diferentes partes do colmo (base, meio e ponta em três períodos da safra (maio a dezembro de três variedades (RB72454, RB835486 e RB 867515 em uma área sob manejo orgânico. O caldo da ponta (do 11º internó até a ponta do colmo poderia ser indicado para a preparação do fermento caipira por ser uma fonte de leveduras e açúcares redutores, especialmente da variedade RB867515. Devido ao efeito da sazonalidade, o melhor período para utilizar esta parte do colmo da cana é no início da safra, quando os compostos fenólicos estão em baixa concentração, mas com altos números de Saccharomyces e de outras leveduras. A alta acidez encontrada nesta parte do colmo poderia resultar num controle mais efetivo dos contaminantes bacterianos. Estes resultados explicam as instruções tradicionais para adição da ponta da cana para o preparo do fermento caipira e podem ajudar no seu manejo a fim de obter um melhor desempenho, no contexto da produção da cachaça orgânica inclusive.

  7. Produção biotecnológica de L-asparaginase(ASP3) de Saccharomyces cerevisiae em sistema de expressão heterólogo Pichia pastoris

    OpenAIRE

    Rafaela Coelho Correia

    2015-01-01

    A leucemia linfóide aguda (LLA) é considerada uma doença grave dos glóbulos brancos, sendo mais comum e mais agressiva em crianças e adolescentes. O tratamento para a LLA tem avançado devido aos estudos para a otimização de drogas já utilizadas em quimioterapias. Entre essas drogas estão as enzimas L- asparaginases (ASPases) que atuam reduzindo a concentração de L-asparagina (Asn) na corrente sanguínea, impedindo a proliferação das células cancerosas, visto que essas não conseguem sintetizar ...

  8. Caracterização de terminadores e promotores para otimização do fluxo metabólico de xilose em Saccharomyces cerevisiae linhagem industrial PE-2 : Characterization of promoters and terminators to optimize the metabolic flux of xylose in Saccharomyces cerevisiae industrial strain PE-2

    OpenAIRE

    Gabriel Vieira Santello

    2016-01-01

    Avanços biotecnológicos introduziram recentemente mudanças em muitos setores da indústria a fim de promover o uso de recursos renováveis para produzir moléculas de relevância econômica, tais como o etanol. O uso de biomassa vegetal para a produção de combustíveis renováveis tem atraído muita atenção, mas a viabilidade de tal processo depende do desenvolvimento de organismos geneticamente modificados capazes de consumir eficientemente açúcares de 5 carbonos abundantes nesse material e tolerar ...

  9. 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 that the a......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...... that the application of the existing methods of genome, transcriptome, proteome and metabolome analysis to other fungi has enormous potential, especially for the production of food and food ingredients. The developments in the past year demonstrate that we have only just started to exploit this potential....

  10. Glucose repression in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Kayikci, Omur; Nielsen, Jens

    2015-01-01

    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 gluc......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...

  11. Funções da proteína Pso9/Mec3 no controle do ciclo celular e reparação de DNA em Saccharomyces cerevisiae

    OpenAIRE

    Jacqueline Moraes Cardone

    2006-01-01

    A manutenção da estabilidade do material hereditário das células requer fidelidade na replicação do DNA, precisão na segregação dos cromossomos e a capacidade de evitar mutações herdáveis, causadas por injúrias espontâneas e induzidas no genoma. Para enfrentar estes desafios, as células possuem processos evolutivamente conservados, incluindo reparação do DNA e mecanismos de checkpoint. Falhas no cumprimento destes mecanismos podem resultar em morte celular, no acúmulo de mutações herdáveis e ...

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

    Directory of Open Access Journals (Sweden)

    Kemal Çelýk

    2003-06-01

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

  13. Progress in Metabolic Engineering of Saccharomyces cerevisiae

    OpenAIRE

    Nevoigt, Elke

    2008-01-01

    Summary: The traditional use of the yeast Saccharomyces cerevisiae in alcoholic fermentation has, over time, resulted in substantial accumulated knowledge concerning genetics, physiology, and biochemistry as well as genetic engineering and fermentation technologies. S. cerevisiae has become a platform organism for developing metabolic engineering strategies, methods, and tools. The current review discusses the relevance of several engineering strategies, such as rational and inverse metabolic...

  14. Heterooligomeric phosphoribosyl diphosphate synthase of Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Hove-Jensen, Bjarne

    2004-01-01

    The yeast Saccharomyces cerevisiae contains five phosphoribosyl diphosphate (PRPP) synthase-homologous genes (PRS1-5), which specify PRPP synthase subunits 1-5. Expression of the five S. cerevisiae PRS genes individually in an Escherichia coli PRPP-less strain (Deltaprs) showed that a single PRS...

  15. Fatal Saccharomyces Cerevisiae Aortic Graft Infection

    Science.gov (United States)

    Meyer, Michael (Technical Monitor); Smith, Davey; Metzgar, David; Wills, Christopher; Fierer, Joshua

    2002-01-01

    Saccharomyces cerevisiae is a yeast commonly used in baking and a frequent colonizer of human mucosal surfaces. It is considered relatively nonpathogenic in immunocompetent adults. We present a case of S. cerevisiae fungemia and aortic graft infection in an immunocompetent adult. This is the first reported case of S. cerevisiue fungemia where the identity of the pathogen was confirmed by rRNA sequencing.

  16. Efeitos do processamento térmico e da radiação gama na estabilidade físico-química, microbiológica e sensorial de caldo de cana puro e adicionado de suco de frutas, armazenado sob refrigeração

    OpenAIRE

    Aline Cristine Garcia Oliveira

    2007-01-01

    O caldo de cana é uma bebida saborosa, energética, não alcoólica que conserva todos os nutrientes presentes na cana-de-açúcar, muito apreciado no Brasil que, se devidamente explorado, pode alcançar um mercado consumidor com proporções ainda maiores. O presente trabalho teve como objetivos avaliar o grau de aceitação do mercado consumidor e a estabilidade do caldo de cana puro e adicionado de suco de frutas, submetido ao processamento térmico (70°C/ 25 min) e/ ou à radiação gama (2,5 kGy)...

  17. Acetylation dynamics and stoichiometry in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Weinert, Brian Tate; Iesmantavicius, Vytautas; Moustafa, Tarek;

    2014-01-01

    Lysine acetylation is a frequently occurring posttranslational modification; however, little is known about the origin and regulation of most sites. Here we used quantitative mass spectrometry to analyze acetylation dynamics and stoichiometry in Saccharomyces cerevisiae. We found that acetylation...

  18. Effects of pentamidine isethionate on Saccharomyces cerevisiae.

    OpenAIRE

    Ludewig, G.; Williams, J M; Li, Y.; Staben, C

    1994-01-01

    We used Saccharomyces cerevisiae as a model system in which to examine the mechanism of action of the anti-Pneumocystis drug pentamidine. Pentamidine at low concentrations inhibited S. cerevisiae growth on nonfermentable carbon sources (50% inhibitory concentration [IC50] of 1.25 micrograms/ml in glycerol). Pentamidine inhibited growth on fermentable energy sources only at much higher concentrations (IC50 of 250 micrograms/ml in glucose). Inhibition at low pentamidine concentrations in glycer...

  19. Spittlebug infestation in sugarcane affects ethanolic fermentation A infestação de cigarrinha-das-raízes em cana-de-açúcar afeta a fermentação etanólica

    Directory of Open Access Journals (Sweden)

    Gisele Cristina Ravaneli

    2006-12-01

    Full Text Available The spittlebug (Mahanarva fimbriolata has become a key pest of the sugarcane crop in Brazil with the increase of green-cane harvesting, causing stalk yield and cane quality losses. This research was undertaken to evaluate the effects of the spittlebug (Mahanarva fimbriolata on cane quality and juice fermentation. The experiment was arranged in a completely randomized 5 × 2 factorial design, with five spittlebug infestation levels (0-0.5; 0.6-2.5; 2.6-5; 5.1-8; 8.1-12.5 nymphs m-1, controlled or not with thiamethoxam (0.2 kg of active ingredient ha-1. To conduct fermentation, Saccharomyces cerevisiae (fresh and pressed baker's yeast was inoculated to musts at a concentration of 30 g L-1. Microbiological analyses were performed at the beginning, middle and end of the fermentation process. The alcohol content and total residual reducing sugars were measured in the wine. Spittlebug attack influenced negatively sugarcane quality, yeast cell and bud viability, and wine alcohol content. Insecticide application resulted in higher cane quality and cell and bud viabilities, resulting in increased fermentation yield.A cigarrinha-das-raízes (Mahanarva fimbriolata tornou-se praga-chave na cultura da cana-de-açúcar com a expansão das áreas de colheita sem queima, comprometendo a produtividade e a qualidade da matéria-prima e consequentemente o processamento industrial. Essa pesquisa objetivou avaliar os efeitos da cigarrinha-das-raízes (Mahanarva fimbriolata sobre a qualidade da cana-de-açúcar e a fermentação do caldo. O delineamento experimental utilizado foi inteiramente casualizado, em esquema fatorial 5 × 2, sendo cinco níveis iniciais de infestação da cigarrinha-das-raízes (0-0,5; 0,6-2,5; 2,6-5; 5,1-8; 8,1-12,5 ninfas m-1, controlados ou não com o inseticida thiamethoxam (0,2 kg de ingrediente ativo ha-1. Para a fermentação alcoólica, o fermento prensado Saccharomyces cerevisiae foi inoculado aos mostos na concentração de 30 g L-1

  20. Compositions and methods for modeling Saccharomyces cerevisiae metabolism

    DEFF Research Database (Denmark)

    2012-01-01

    The invention provides an in silica model for determining a S. cerevisiae physiological function. The model includes a data structure relating a plurality of S. cerevisiae reactants to a plurality of S. cerevisiae reactions, a constraint set for the plurality of S. cerevisiae reactions......, and commands for determining a distribution of flux through the reactions that is predictive of a S. cerevisiae physiological function. A model of the invention can further include a gene database containing information characterizing the associated gene or genes. The invention further provides methods...... for making an in silica S. cerevisiae model and methods for determining a S. cerevisiae physiological function using a model of the invention. The invention provides an in silica model for determining a S. cerevisiae physiological function. The model includes a data structure relating a plurality of S...

  1. Integral Membrane Protein Expression in Saccharomyces cerevisiae.

    Science.gov (United States)

    Boswell-Casteel, Rebba C; Johnson, Jennifer M; Stroud, Robert M; Hays, Franklin A

    2016-01-01

    Eukaryotic integral membrane proteins are challenging targets for crystallography or functional characterization in a purified state. Since expression is often a limiting factor when studying this difficult class of biological macromolecules, the intent of this chapter is to focus on the expression of eukaryotic integral membrane proteins (IMPs) using the model organism Saccharomyces cerevisiae. S. cerevisiae is a prime candidate for the expression of eukaryotic IMPs because it offers the convenience of using episomal expression plasmids, selection of positive transformants, posttranslational modifications, and it can properly fold and target IMPs. Here we present a generalized protocol and insights based on our collective knowledge as an aid to overcoming the challenges faced when expressing eukaryotic IMPs in S. cerevisiae.

  2. Transfer RNA pseudouridine synthases in Saccharomyces cerevisiae.

    Science.gov (United States)

    Samuelsson, T; Olsson, M

    1990-05-25

    A transfer RNA lacking modified nucleosides was produced by transcription in vitro of a cloned gene that encodes a Saccharomyces cerevisiae glycine tRNA. At least three different uridines (in nucleotide positions 13, 32, and 55) of this transcript tRNA are modified to pseudouridine by an extract of S. cerevisiae. Variants of the RNA substrate were also constructed that each had only one of these sites, thus allowing specific monitoring of pseudouridylation at different nucleotide positions. Using such RNAs to assay pseudouridine synthesis, enzymes producing this nucleoside were purified from an extract of S. cerevisiae. The activities corresponding to positions 13, 32, and 55 in the tRNA substrate could all be separated chromatographically, indicating that there is a separate enzyme for each of these sites. The enzyme specific for position 55 (denoted pseudouridine synthase 55) was purified approximately 4000-fold using a combination of DEAE-Sepharose, heparin-Sepharose, and hydroxylapatite.

  3. Produção de bioetanol a partir da fermentaçãode caldo de sorgo sacarino e cana-de-açúcar

    Directory of Open Access Journals (Sweden)

    Igor dos Santos Masson

    2015-09-01

    Full Text Available Os biocombustíveis apresentam-se com grande importância para suprir a demanda global de energia. São produzidos a partir de biomassa vegetal, emitem menor quantidade de dióxido de carbono e de partículas poluentes ao ambiente quando utilizados e possuem grande vantagem por serem combustíveis renováveis. Entre as matérias-primas com potencial para produção de etanol, cita-se o sorgo sacarino. Objetivou-se comparar o processamento industrial do genótipo de sorgo sacarino CVSW80007 e da cultivar de cana-de-açúcar 'RB966928' para produção de bioetanol em início de safra. As análises realizadas foram: brix; pH, ART, AR, acidez total, ARRT, glicerol, teor alcoolico, viabilidade celular, viabilidade de brotos e brotamentos. Quanto às características químico-tecnológicas, as matérias-primas apresentaram-se aptas ao processamento industrial, com índices superiores para a cana-de-açúcar. O desenvolvimento das fermentações ocorreu de forma adequada para ambas, sendo que o mosto fermentado (vinho, produzido a partir do mosto de cana-de-açúcar, apresentou maior teor alcoolico e rendimento fermentativo.

  4. Characteristics of sterol uptake in Saccharomyces cerevisiae.

    OpenAIRE

    Lorenz, R T; Rodriguez, R J; Lewis, T A; Parks, L W

    1986-01-01

    A Saccharomyces cerevisiae sterol auxotroph, FY3 (alpha hem1 erg7 ura), was used to probe the characteristics of sterol uptake in S. cerevisiae. The steady-state cellular concentration of free sterol at the late exponential phase of growth could be adjusted within a 10-fold range by varying the concentration of exogenously supplied sterol. When cultured on 1 microgram of sterol ml-1, the cells contained a minimal cellular free-cholesterol concentration of 0.85 nmol/mg (dry weight) and were te...

  5. Application of a method for the determination of yeast cell density to studies on the sedimentation of Saccharomyces cerevisiae in alcoholic fermentation broths; Aplicacao de metodo para a determinacao da densidade de celulas de leveduras a estudos sobre sedimentacao de Aaccharomyces cerecisiae em mostos de fermentacao alcoolica

    Energy Technology Data Exchange (ETDEWEB)

    Maia, Amazile B.R.A. [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Escola de Engenharia. Dept. de Engenharia Quimica; Nelson, David Lee [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Faculdade de Farmacia. Dept. de Alimentos

    1993-09-01

    A technique that permitted the determination of the Saccharomyces cerevisiae cell density was developed. The average results (1,04 g/ml) attributed to the cells under the conditions of the effected tests, was applied to a previously developed mathematical model for predicting the clarification velocity of alcoholic fermentation broths in a sedimenter prototype designed for accelerating the sedimentation of cells. (author) 19 refs., 1 fig., 4 tabs.

  6. Flocculation of Saccharomyces cerevisiae tup1 mutants.

    OpenAIRE

    1984-01-01

    Strains of Saccharomyces cerevisiae carrying a mutation in the TUP1 locus exhibited calcium-dependent flocculation. The flocculation had none of the characteristics of sexual agglutination. The flocculation differed from that exhibited by a FLO1 strain in the effect of pH on cation dependence and sensitivity to chemical inactivation.

  7. Tangential Ultrafiltration of Aqueous "Saccharomyces Cerevisiae" Suspensions

    Science.gov (United States)

    Silva, Carlos M.; Neves, Patricia S.; Da Silva, Francisco A.; Xavier, Ana M. R. B.; Eusebio, M. F. J.

    2008-01-01

    Experimental work on ultrafiltration is presented to illustrate the practical and theoretical principles of this separation technique. The laboratory exercise comprises experiments with pure water and with aqueous "Saccharomyces cerevisiae" (from commercial Baker's yeast) suspensions. With this work students detect the characteristic phenomena…

  8. Nitrogen Catabolite Repression in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Hofman-Bang, H Jacob Peider

    1999-01-01

    In Saccharomyces cerevisiae the expression of all known nitrogen catabolite pathways are regulated by four regulators known as Gln3, Gat1, Da180, and Deh1. This is known as nitrogen catabolite repression (NCR). They bind to motifs in the promoter region to the consensus sequence S' GATAA 3'. Gln3...

  9. Elucidating TOR Signaling and Rapamycin Action: Lessons from Saccharomyces cerevisiae

    OpenAIRE

    Crespo, José L; Hall, Michael N.

    2002-01-01

    TOR (target of rapamycin) is a phosphatidylinositol kinase-related protein kinase that controls cell growth in response to nutrients. Rapamycin is an immunosuppressive and anticancer drug that acts by inhibiting TOR. The modes of action of TOR and rapamycin are remarkably conserved from S. cerevisiae to humans. The current understanding of TOR and rapamycin is derived largely from studies with S. cerevisiae. In this review, we discuss the contributions made by S. cerevisiae to understanding r...

  10. Genome-scale reconstruction of the Saccharomyces cerevisiae metabolic network

    DEFF Research Database (Denmark)

    Förster, Jochen; Famili, I.; Fu, P.;

    2003-01-01

    The metabolic network in the yeast Saccharomyces cerevisiae was reconstructed using currently available genomic, biochemical, and physiological information. The metabolic reactions were compartmentalized between the cytosol and the mitochondria, and transport steps between the compartments...... containing 1175 metabolic reactions and 584 metabolites. The number of gene functions included in the reconstructed network corresponds to similar to16% of all characterized ORFs in S. cerevisiae. Using the reconstructed network, the metabolic capabilities of S. cerevisiae were calculated and compared...

  11. Synthesis of Morphinan Alkaloids in Saccharomyces cerevisiae.

    Directory of Open Access Journals (Sweden)

    Elena Fossati

    Full Text Available Morphinan alkaloids are the most powerful narcotic analgesics currently used to treat moderate to severe and chronic pain. The feasibility of morphinan synthesis in recombinant Saccharomyces cerevisiae starting from the precursor (R,S-norlaudanosoline was investigated. Chiral analysis of the reticuline produced by the expression of opium poppy methyltransferases showed strict enantioselectivity for (S-reticuline starting from (R,S-norlaudanosoline. In addition, the P. somniferum enzymes salutaridine synthase (PsSAS, salutaridine reductase (PsSAR and salutaridinol acetyltransferase (PsSAT were functionally co-expressed in S. cerevisiae and optimization of the pH conditions allowed for productive spontaneous rearrangement of salutaridinol-7-O-acetate and synthesis of thebaine from (R-reticuline. Finally, we reconstituted a 7-gene pathway for the production of codeine and morphine from (R-reticuline. Yeast cell feeding assays using (R-reticuline, salutaridine or codeine as substrates showed that all enzymes were functionally co-expressed in yeast and that activity of salutaridine reductase and codeine-O-demethylase likely limit flux to morphine synthesis. The results of this study describe a significant advance for the synthesis of morphinans in S. cerevisiae and pave the way for their complete synthesis in recombinant microbes.

  12. Saccharomyces cerevisiae metabolism in ecological context

    Science.gov (United States)

    Jouhten, Paula; Ponomarova, Olga; Gonzalez, Ramon; Patil, Kiran R.

    2016-01-01

    The architecture and regulation of Saccharomyces cerevisiae metabolic network are among the best studied owing to its widespread use in both basic research and industry. Yet, several recent studies have revealed notable limitations in explaining genotype–metabolic phenotype relations in this yeast, especially when concerning multiple genetic/environmental perturbations. Apparently unexpected genotype–phenotype relations may originate in the evolutionarily shaped cellular operating principles being hidden in common laboratory conditions. Predecessors of laboratory S. cerevisiae strains, the wild and the domesticated yeasts, have been evolutionarily shaped by highly variable environments, very distinct from laboratory conditions, and most interestingly by social life within microbial communities. Here we present a brief review of the genotypic and phenotypic peculiarities of S. cerevisiae in the context of its social lifestyle beyond laboratory environments. Accounting for this ecological context and the origin of the laboratory strains in experimental design and data analysis would be essential in improving the understanding of genotype–environment–phenotype relationships. PMID:27634775

  13. 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...

  14. Potential immobilized Saccharomyces cerevisiae as heavy metal removal

    Science.gov (United States)

    Raffar, Nur Izzati Abdul; Rahman, Nadhratul Nur Ain Abdul; Alrozi, Rasyidah; Senusi, Faraziehan; Chang, Siu Hua

    2015-05-01

    Biosorption of copper ion using treated and untreated immobilized Saccharomyces cerevisiae from aqueous solution was investigate in this study. S.cerevisiae has been choosing as biosorbent due to low cost, easy and continuously available from various industries. In this study, the ability of treated and untreated immobilized S.cerevisiae in removing copper ion influence by the effect of pH solution, and initial concentration of copper ion with contact time. Besides, adsorption isotherm and kinetic model also studied. The result indicated that the copper ion uptake on treated and untreated immobilized S.cerevisiae was increased with increasing of contact time and initial concentration of copper ion. The optimum pH for copper ion uptake on untreated and treated immobilized S.cerevisiae at 4 and 6. From the data obtained of copper ion uptake, the adsorption isotherm was fitted well by Freundlich model for treated immobilized S.cerevisiae and Langmuir model for untreated immobilized S.cerevisiae according to high correlation coefficient. Meanwhile, the pseudo second order was described as suitable model present according to high correlation coefficient. Since the application of biosorption process has been received more attention from numerous researchers as a potential process to be applied in the industry, future study will be conducted to investigate the potential of immobilized S.cerevisiae in continuous process.

  15. 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...

  16. Detecção dos genes codificantes da toxina CDT, e pesquisa de fatores que influenciam na produção de hemolisinas em amostras de Campylobacter jejuni de origem avícola

    Directory of Open Access Journals (Sweden)

    Michele M. Trindade

    2015-08-01

    Full Text Available Resumo: Membros termofílicos do gênero Campylobacter são reconhecidos como importantes enteropatógenos para o ser humano e animais. A grande diversidade ecológica destes micro-organismos em diferentes habitats tais como água, animais e alimentos predispõem ao aparecimento de novos fatores de virulência. Este trabalho teve por objetivo detectar os genes codificantes da Toxina Distensiva Citoletal (CDT por meio da técnica de PCR, pesquisar a atividade de hemolisinas e a influência de soluções quelantes e de íons nesta atividade. Foram utilizadas 45 amostras de Campylobacter jejuni de origem avícola para pesquisa de atividade hemolítica, cultivadas em Caldo Triptona de Soja (TSB. Após o crescimento bacteriano, as amostras foram semeadas em Ágar tríptico de soja (TSA contendo 5% de sangue de ovino. Para verificar a influência de agentes quelantes e solução de íons na atividade hemolítica, as amostras de C. jejuni foram cultivadas em TSB contendo separadamente os quelantes EDTA, ácido acético, soluções de íons CaCl2, MgCl2 e FeCl3, em atmosfera de microaerofilia. Quanto à atividade de hemolisina de C. jejuni em placas de TSA - sangue ovino foi possível observar que houve hemólise em 40% das amostras analisadas apenas com caldo TSB. Somente o ácido acético apresentou ação quelante sobre a atividade de hemolisinas em amostras de C. jejuni semeadas em placas de TSA - sangue ovino. Para detecção dos genes cdtA, cdtB e cdtC através da técnica da Reação em Cadeia da Polimerase (PCR foram utilizadas 119 amostras de C. jejuni de origem avícola. Foi possível observar que 37,8% possuíam o perfil de genes cdtABC. Os resultados demonstraram em amostras avícolas a presença de cepas de C. jejuni com potencial virulento, devido à presença dos genes da toxina CDT e potencial hemolítico, que apresentou ação reduzida in vitro com ácido acético.

  17. Beta-glucana from Saccharomyces cerevisiae: constitution, bioactivity and obtaining / Beta-glucana de Saccharomyces cerevisiae: constituição, bioatividade e obtenção

    Directory of Open Access Journals (Sweden)

    Raul Jorge Hernan Castro-Gómez

    2008-08-01

    Full Text Available b-glucans are polysaccharides that constitute the structure of the cell wall of yeast, fungi and some cereals, which differs each other by the linkages between glucose units. An important source of these polymers is the Saccharomyces cerevisiae cell wall, which is a yeast widely used in industrial processes of fermentation. The b-glucan is considered to be a modifier of biological response due to its immunomodulator potential. When it is recognized by specific cellular receptors, have the ability to enhance the host’s immune response. Other beneficial effects such as anticarcinogenic, antimutagenic, hypocholesterolemic and blood sugar reduction have also been related to the b-glucan. The aim of this literature review was expand scientific knowledge about the constitution and bioactivity of b-glucan, including its recognition by the immune system, as well as its obtaining from S. cerevisiae cell wall.b-glucanas são polissacarídeos constituintes estruturais da parede celular de leveduras, fungos e alguns cereais, que se diferenciam pelo tipo de ligação presente entre as unidades de glicose. Uma importante fonte destes polissacarídeos é a parede celular de Saccharomyces cerevisiae, uma levedura amplamente empregada em processos industriais de fermentação. A b-glucana é considerada um modificador da resposta biológica devido ao seu potencial imunomodulador, pois ao ser reconhecida por receptores celulares específicos tem habilidade de realçar a resposta imune do hospedeiro. Outros efeitos benéficos como anticarcinogênico, antimutagênico, hipocolesterolêmico e hipoglicêmico também têm sido relacionados à b-glucana Esta revisão de literatura teve por objetivo agregar conhecimentos científicos sobre a constituição e bioatividade da b glucana, incluindo seu reconhecimento pelo sistema imune, bem como, a obtenção a partir da parede celular de S. cerevisiae.

  18. Controle de doenças foliares e de flores e qualidade pós-colheita do morangueiro tratado com Saccharomyces cerevisiae Control of leaf and flower diseases and postharvest quality of strawberry plants treated with Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Alfredo de Gouvea

    2009-12-01

    Full Text Available O efeito de diferentes preparações de Saccharomyces cerevisiae foi avaliado sobre o desenvolvimento das doenças do morangueiro, como mancha-de-micosferela (Mycosphaerella fragariae, mancha-de-dendrofoma (Dendrophoma obscurans e flor-preta (Colletotrichum acutatum além da qualidade pós-colheita dos frutos. O trabalho foi realizado entre 2004 e 2005 na Universidade Tecnológica Federal do Paraná, Campus Dois Vizinhos. Os tratamentos consistiram de pulverizações semanais de cinco diferentes preparados a partir da levedura S. cerevisiae: suspensão com fermento biológico fresco comercial, suspensão de células de levedura, suspensão autoclavada de células, filtrado de cultura em meio líquido e Agro-MOS®, produto comercial formulado a partir da levedura, além da testemunha com água destilada e do tratamento controle com fungicidas. Nenhuma das preparações apresentou efeito contra a mancha-de-micosferela; preparações com a presença de células vivas e o produto Agro-MOS® apresentaram efeito contra mancha-de-dendrofoma; preparações com suspensão do produto comercial e filtrado de cultura líquida reduziram a incidência de flor-preta em flores e frutos. Preparações de S. cerevisiae com suspensão de células, suspensão autoclavada de células e filtrado de cultura líquida promoveram aumento na produtividade dos morangueiros que variou de 589,6 a 617,8 g planta-1. Preparações de S. cerevisiae, com presença de células vivas ou não, alteraram o metabolismo do morangueiro, aumentando a atividade das enzimas quitinase e glucanase, envolvidas na resistência sistêmica adquirida. Todos os tratamentos, com exceção do tratamento com suspensão autoclavada de células, reduziram a incidência de mofo-cinzento em pós-colheita de frutos.The effect of Saccharomyces cerevisiae was evaluated on the development of strawberry diseases and postharvest quality of fruits. The research was carried out in 2004 and 2005 in Paraná State

  19. 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

    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...

  20. Isocitrate lyase localisation in Saccharomyces cerevisiae cells.

    Science.gov (United States)

    Chaves, R S; Herrero, P; Ordiz, I; Angeles del Brio, M; Moreno, F

    1997-10-01

    The isocitrate lyase from Saccharomyces cerevisiae was only located in the cell cytoplasm. This protein was found not to be associated with cell organelles, even under growth conditions that induce peroxisome proliferation. This conclusion is supported by experiments carried out by damaging the protoplast plasma membrane with DEAE-dextran, by differential centrifugation of osmotically lysed protoplast and by using the green fluorescent protein (GFP) of Aequorea victoria as a reporter fusion tag to localise the subcellular compartment to which isocitrate lyase is targeted.

  1. Efficient screening of environmental isolates for Saccharomyces cerevisiae strains that are suitable for brewing.

    Science.gov (United States)

    Fujihara, Hidehiko; Hino, Mika; Takashita, Hideharu; Kajiwara, Yasuhiro; Okamoto, Keiko; Furukawa, Kensuke

    2014-01-01

    We developed an efficient screening method for Saccharomyces cerevisiae strains from environmental isolates. MultiPlex PCR was performed targeting four brewing S. cerevisiae genes (SSU1, AWA1, BIO6, and FLO1). At least three genes among the four were amplified from all S. cerevisiae strains. The use of this method allowed us to successfully obtain S. cerevisiae strains.

  2. Role of Nab2 in RNA metabolism in <em>Saccharomyces cerevisiae>

    DEFF Research Database (Denmark)

    Olszewski, Pawel

    RNP assembly generates errors, which are tracked down by nuclear surveillance mechanisms. Thus, not surprisingly, protein components of mRNPs have multiple functions in the biogenesis of the particle but also interact with the surveillance machinery. An example of such a multifunctional factor is the S......RNP components showed changes in the Nab2 interactome in the absence of Rrp6, and also suggested that Nab2 binds to multiple sites on the mRNA. Wide-range proteomic analysis of Nab2 immunoprecipitates revealed association with C/D box snoRNP components. These novel interactions were supported by the presence...

  3. Response of Saccharomyces cerevisiae to cadmium stress

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Luciana Mara Costa; Ribeiro, Frederico Haddad; Neves, Maria Jose [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Lab. de Radiobiologia], e-mail: luamatu@uol.com.br; Porto, Barbara Abranches Araujo; Amaral, Angela M.; Menezes, Maria Angela B.C. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Lab. de Ativacao Neutronica], e-mail: menezes@cdtn.br; Rosa, Carlos Augusto [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Microbiologia], e-mail: carlrosa@icb.ufmg

    2009-07-01

    The intensification of industrial activity has been greatly contributing with the increase of heavy metals in the environment. Among these heavy metals, cadmium becomes a serious pervasive environmental pollutant. The cadmium is a heavy metal with no biological function, very toxic and carcinogenic at low concentrations. The toxicity of cadmium and several other metals can be mainly attributed to the multiplicity of coordination complexes and clusters that they can form. Some aspects of the cellular response to cadmium were extensively investigated in the yeast Saccharomyces cerevisiae. The primary site of interaction between many toxic metals and microbial cells is the plasma membrane. Plasma-membrane permeabilisation has been reported in a variety of microorganisms following cadmium exposure, and is considered one mechanism of cadmium toxicity in the yeast. In this work, using the yeast strain S. cerevisiae W303-WT, we have investigated the relationships between Cd uptake and release of cellular metal ions (K{sup +} and Na{sup +}) using neutron activation technique. The neutron activation was an easy, rapid and suitable technique for doing these metal determinations on yeast cells; was observed the change in morphology of the strains during the process of Cd accumulation, these alterations were observed by Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) during incorporation of cadmium. (author)

  4. Avaliação do uso de leveduras (Saccharomyces cerevisiae) inativas e hidrolizadas nas dietas iniciais de leitões

    OpenAIRE

    2010-01-01

    O objetivo deste trabalho foi avaliar a adição de diferentes níveis de levedura (Saccharomyces cerevisiae) inativa e desidratada às rações, associados ao plasma sangüíneo e ao ácido glutâmico, sobre o desempenho e morfologia intestinal de leitões na fase inicial. Para tanto, foram realizados dois experimentos, cada um com três tratamentos de quatro repetição com 22 animais em fase de creche (21 à 59 dias), totalizando 264 leitões por experimento. Os animais foram distribuídos em delineamento ...

  5. 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

    Directory of Open Access Journals (Sweden)

    R. Ferreira

    2007-01-01

    Full Text Available A fermentação do vinho é um processo microbiológico complexo que requere a presença de leveduras adaptadas a condições de stresse. No ambiente celular de organismos aeróbios ocorrem naturalmente espécies reactivas de oxigénio (ROS como subprodutos da respiração mitocondrial. A elevada reactividade destas espécies químicas pode gerar danos moleculares que, em alguns casos, levam à morte celular. Em condições fisiológicas normais ou como resposta ao stresse oxidativo, a célula pode desencadear respostas adaptativas que envolvem mecanismos antioxidantes como os enzimas glutationo redutase (GR; EC 1.6.4.2 e catalases T (CAT T; EC 1.11.1.6 e A (CAT A; EC 1.11.1.6. O vanádio, um metal pesado presente em alguns fitofármacos, pode também com portar-se como um gerador de ROS, alterando o estado redox intracelular e exercendo efeitos nocivos em leveduras expostas a quantidade excessiva deste elemento. O principal objectivo deste trabalho foi comparar o efeito do metavanadato de amónio (NH4VO3, um sal pentavalente de vanádio, na viabilidade celular e nas actividades enzimáticas GR, CAT T e CAT A das leveduras vínicas Saccharomyces cerevisiae UE-ME3 e Saccharomyces chevalieri UE-ME1. Os resultados obtidos mostram que S. chevalieri UE-ME1 revelou menor tolerância ao NH4VO3 do que S. cerevisiae UE-ME3, uma vez que culturas de S. chevalieri não sobreviveram para valores de concentração do sal de vanádio superiores a 7,5 mM enquanto que células de S. cerevisiae mantiveram-se viáveis em presença de metavanadato de amónio 75 mM. As actividades enzimáticas estudadas apresentaram em S. chevalieri valores muito inferiores aos que foram determinados em S. cerevisiae embora em ambas as espécies de levedura o NH4VO3 pareça comportarse como um indutor de stresse oxidativo ao provocar um decréscimo significativo da actividade GR (PThe fermentation of wine is a complex microbiological process which requires yeast adaptation to stress

  6. Increasing NADH oxidation reduces overflow metabolism in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Vemuri, Goutham; Eiteman, M.A; McEwen, J.E;

    2007-01-01

    Crabtree effect.’’ The yeast Saccharomyces cerevisiae has served as an important model organism for studying the Crabtree effect. When subjected to increasing glycolytic fluxes under aerobic conditions, there is a threshold value of the glucose uptake rate at which the metabolism shifts from purely...... effect is due to limited respiratory capacity or is caused by glucose-mediated repression of respiration. When respiration in S. cerevisiae was increased by introducing a heterologous alternative oxidase, we observed reduced aerobic ethanol formation. In contrast, increasing nonrespiratory NADH oxidation...... NADH dehydrogenases in S. cerevisiae. These results indicate that NADH oxidase localizes in the cytosol, whereas alternative oxidase is directed to the mitochondria....

  7. Obtención por Ɣ-irradiación de cepas de Saccharomyces cerevisiae tolerantes a condiciones de cultivo rigurosas, para la producción de bioetanol

    Directory of Open Access Journals (Sweden)

    Sylvia Enid Vazquez Zeballos

    2013-01-01

    Full Text Available Con el objetivo de obtener nuevas cepas de levadura capaces de resistir condiciones rigurosas de cultivo se sometió un cultivo fresco de Saccharomyces cerevisiae M522 a Ɣ-irradiación. Se generó una colección de cepas y se evaluó su capacidad de crecimiento a elevadas concentraciones de azúcar y etanol. Se seleccionó una de las cepas y se estudió en ella el efecto de los productos de degradación de la lignina, oligómeros fenólicos metoxilados obtenidos de su despolimerización oxidativa por tratamiento biológico. Se estudiaron también las enzimas involucradas. Todos los cultivos fueron evaluados por absorbancia a 660 nm tras 24 horas de incubación a 37 ˚C. En cuanto a las fracciones fenólicas, se obtuvo el perfil por espectrofotometría UV y se identificaron enzimas laccasa, desmetilasa y lig-peroxidasa.Se obtuvo una cepa (SacSV-10 con las mismas características de cultivo que la M522 en YPD. Se logró cultivar la cepa en un caldo con 10 % de etanol, cepa que toleró el efecto de los productos de degradación de la lignina, así como una concentración de glucosa de 40 g/L, y en condiciones anaerobias se obtuvo una biomasa mayor que para la M522. En conclusión, SacSV-10 es un prometedor candidato para usar en producciones de alcohol a partir de residuos lignocelulósicos.

  8. Comparação de Meios de Enriquecimento e de Plaqueamento Utilizados na Pesquisa de Salmonella em Carcaças de Frango e Fezes de Aves Comparison of Different Enrichment Broth and Plating Media Used to Isolating Salmonella from Chicken Carcasses and Poultry Faeces Samples

    Directory of Open Access Journals (Sweden)

    MS Nascimento

    2000-04-01

    Full Text Available Este trabalho foi desenvolvido para avaliar, comparativamente, os caldos de enriquecimento Rapapport-novobiocina (RVN, selenito-cistinanovobiocina (SCN e tetrationato-novobiocina (TN e os meios para plaqueamento ágar Hektoen (HE, ágar MacConkey (MC, ágar Salmonella-Shigella (SS, ágar verde brilhante (VB e ágar xilose lisina desoxicolato (XLD, utilizados no isolamento de Salmonella em carcaças de frango e fezes de aves. O procedimento bacteriológico consistiu das etapas de pré-enriquecimento, enriquecimento em caldos seletivos, plaqueamento, testes bioquímicos presuntivos e confirmação sorológica com soros polivalentes anti antígenos somáticos e flagelares de Salmonella.. As fezes foram experimentalmente contaminadas com 8 sorotipos de Salmonella (Agona, Anatum, Enteritidis, Havana, Infantis, Owakam, Schwazengrund e Typhimurium e a concentração final foi aproximadamente de 1,2 x 10² ufc/g. As fezes foram inoculadas nos caldos enriquecedores e a partir daí, seguiu-se o mesmo procedimento utilizado para as carcaças. Os resultados referentes às carcaças de frango não foram estatisticamente diferentes (p>0,01 para os caldos e as placas. Todavia, verificou-se superioridade numérica em relação aos caldos SCN e TN sobre o caldo RVN, e em relação ao ágar XLD sobre os demais. Verificou-se também que com o emprego de dois caldos de enriquecimento e de dois meios para plaqueamento pode-se obter maior positividade. Quanto ao exame das fezes, o caldo TN mostrou-se superior aos demais (p>0,01, não havendo diferença (p>0,01 de resultados para os meios de plaqueamento. Os resultados sugerem que a utilização de mais de um meio de enriquecimento e de plaqueamento poderia aumentar as chances de isolamento de Salmonella.This study was undertaken to compare selenite-cystine-novobiocin (SCN broth, tetrationate-novobiocin (TN broth and Rappaport-Vassiliadisnovobiocin (RVN broth as enrichment and MacConkey (MC agar, brilliant green (BG

  9. Pesquisa de fatores de virulência em Pseudomonas aeruginosa isoladas de águas minerais naturais

    Directory of Open Access Journals (Sweden)

    Aline Pereira Pedrosa

    2014-04-01

    Full Text Available O objetivo deste estudo foi avaliar a formação de biofilme e o perfil de susceptibilidade a antimicrobianos de Pseudomonas aeruginosa isoladas na avaliação da qualidade microbiológica de 80 amostras de águas minerais naturais comercializadas em garrafões de 20 L. Foi realizada a quantificação de P. aeruginosa e enterococos; a pesquisa de coliformes totais, coliformes termotolerantes e de clostrídios sulfito redutores (CSR. A produção de biofilme de P. aeruginosa foi avaliada em caldo infusão cérebro-coração (BHI e em água mineral natural estéril nas temperaturas de 25 e 35ºC por 24 e 48 h. A avaliação da susceptibilidade a antimicrobianos foi realizada pelo teste de difusão em ágar (Kirby-Bauer. De 80 amostras analisadas, 40 (50% apresentaram qualidade microbiológica insatisfatória segundo a RDC nº275/05. Trinta e oito (47,5% amostras apresentaram P. aeruginosa, nove (11,2% coliformes totais, quatro (5,0% CSR e uma (1,2% coliformes termotolerantes. Nenhuma amostra apresentou contaminação por enterococos. Dezesseis cepas (51,6% de P. aeruginosa foram classificadas como não aderentes ou fracamente aderentes, tanto no BHI quanto na água mineral. Contudo, cinco cepas (16,1% apresentaram-se fortemente aderentes nas duas matrizes, principalmente no caldo BHI e na temperatura de 25ºC. Cepas resistentes ou com resistência intermediária a antibióticos da classe dos aminoglicosídeos e/ou β-lactâmicos foram isoladas neste estudo. Concluiu-se que os isolados de P. aeruginosa foram capazes de produzir biofilme nas matrizes estudadas e apresentaram resistência a antimicrobianos. Metade das amostras apresentou qualidade microbiológica insatisfatória, principalmente devido à contaminação por P. aeruginosa (47,5%.

  10. Molecular Basis for Saccharomyces cerevisiae Biofilm Development

    DEFF Research Database (Denmark)

    Andersen, Kaj Scherz

    of translation of FLO11. In conclusion, I have conducted the first global study of the genetic program for yeast biofilm formation on polystyrene. This work provide several target genes as good basis for further research of biofilm, that I believe can contribute to fields such as cell biology, genetics, system......In this study, I sought to identify genes regulating the global molecular program for development of sessile multicellular communities, also known as biofilm, of the eukaryotic microorganism, Saccharomyces cerevisiae (yeast). Yeast biofilm has a clinical interest, as biofilms can cause chronic......, but only a small subset is previously described as regulators of FLO11. These results reveal that the regulation of biofilm formation and FLO11 is even more complex than what has previously been described. I find that the molecular program for biofilm formation shares many essential components with two...

  11. Synchronization of the Budding Yeast Saccharomyces cerevisiae.

    Science.gov (United States)

    Foltman, Magdalena; Molist, Iago; Sanchez-Diaz, Alberto

    2016-01-01

    A number of model organisms have provided the basis for our understanding of the eukaryotic cell cycle. These model organisms are generally much easier to manipulate than mammalian cells and as such provide amenable tools for extensive genetic and biochemical analysis. One of the most common model organisms used to study the cell cycle is the budding yeast Saccharomyces cerevisiae. This model provides the ability to synchronise cells efficiently at different stages of the cell cycle, which in turn opens up the possibility for extensive and detailed study of mechanisms regulating the eukaryotic cell cycle. Here, we describe methods in which budding yeast cells are arrested at a particular phase of the cell cycle and then released from the block, permitting the study of molecular mechanisms that drive the progression through the cell cycle.

  12. Viruses and prions of Saccharomyces cerevisiae.

    Science.gov (United States)

    Wickner, Reed B; Fujimura, Tsutomu; Esteban, Rosa

    2013-01-01

    Saccharomyces cerevisiae has been a key experimental organism for the study of infectious diseases, including dsRNA viruses, ssRNA viruses, and prions. Studies of the mechanisms of virus and prion replication, virus structure, and structure of the amyloid filaments that are the basis of yeast prions have been at the forefront of such studies in these classes of infectious entities. Yeast has been particularly useful in defining the interactions of the infectious elements with cellular components: chromosomally encoded proteins necessary for blocking the propagation of the viruses and prions, and proteins involved in the expression of viral components. Here, we emphasize the L-A dsRNA virus and its killer-toxin-encoding satellites, the 20S and 23S ssRNA naked viruses, and the several infectious proteins (prions) of yeast.

  13. 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...... sugar found in lignocelluloses. Significant research efforts have focused on the metabolic engineering of S. cerevisiae for fast and efficient xylose utilization. This study aims to metabolically engineer S. cerevisiae, such that it can consume xylose as the exclusive substrate while maximizing carbon......-metabolizing yeast Pichia stipitis, was constructed, followed by a directed evolution strategy to improve xylose utilization rates. The resulting S. cerevisiae strain was capable of rapid growth and fast xylose consumption producing only biomass and negligible amount of byproducts. Transcriptional profiling...

  14. 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...

  15. Utilização da levedura desidratada (Saccharomyces cerevisiae para leitões na fase inicial Dried yeast (Saccharomyces cerevisiae utilization for piglets in the initial phase

    Directory of Open Access Journals (Sweden)

    Lúcio Francelino Araújo

    2006-10-01

    Full Text Available Foi conduzido um experimento com o objetivo de avaliar o efeito da adição de diferentes níveis de levedura (Saccharomyces cerevisiae desidratada na ração sobre o desempenho e a morfologia intestinal de leitões na fase inicial. Foram utilizados 280 leitões (fêmeas e machos castrados de uma linha genética comercial de suínos, desmamados com 21 dias de idade e distribuídos em 20 baias, de acordo com o delineamento em blocos ao acaso, com 5 repetições e 4 tratamentos experimentais (0, 5, 10 e 15% de adição de levedura. Aos 45 dias de idade, três leitões de cada tratamento foram abatidos e colhidas amostras do duodeno e do jejuno para estudo da morfologia intestinal. Os níveis crescentes de levedura desidratada nas rações não afetaram (P>0,05 o ganho de peso, o consumo de ração e a conversão alimentar dos leitões. Com relação à morfologia do duodeno e do jejuno, também não houve efeito (P>0,05 dos níveis de levedura estudados sobre a altura das vilosidades, das profundidades das criptas e da relação vilosidade/cripta. Os resultados permitiram concluir que a levedura desidratada pode ser adicionada em até 15% nas rações de suínos na fase inicial.An experiment was conducted to evaluate the effect of different levels of dried yeast (Saccharomyces cerevisiae in diets about performance and intestinal morphology of piglets at initial phase. They used 280 piglets (females and castrated males from genetic lines, weaned with 21 days of age, allocated in 20 pens in randomized design blocks, with 5 replications and 4 treatments (0, 5, 10 and 15% dried yeast addition. Samples of duodenum and jejunum of 3 piglets slaughtered at 45 days of age were collected from each treatment to study intestinal morphology. The increasing levels of dried yeast in rations did not affect significantly the weight gain, feed intake and feed conversion. In relation of duodenum and jejunum there was no significative effect (P>0.05 of dried yeast

  16. Glucose- and nitrogen sensing and regulatory mechanisms in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Rødkaer, Steven V; Færgeman, Nils J.

    2014-01-01

    steps and by numerous different regulators. As numerous of these regulating proteins, biochemical mechanisms, and cellular pathways are evolutionary conserved, complex biochemical information relevant to humans can be obtained by studying simple organisms. Thus, the yeast Saccharomyces cerevisiae has...... been recognized as a powerful model system to study fundamental biochemical processes. In the present review, we highlight central signaling pathways and molecular circuits conferring nitrogen- and glucose sensing in S. cerevisiae....

  17. Combined application of origanum vulgare l. essential oil and acetic acid for controlling the growth of staphylococcus aureus in foods Aplicação combinada do óleo essencial de Origanum vulgare L. e ácido acético para o controle do crescimento de Staphylococcus aureus em alimentos

    Directory of Open Access Journals (Sweden)

    Evandro Leite de Souza

    2009-06-01

    Full Text Available This study evaluated the occurrence of an enhancing inhibitory effect of the combined application of Origanum vulgare L. essential oil and acetic acid against Staphylococcus aureus by the determination of Fractional Inhibitory Concentration (FIC index and kill-time assay in nutrient broth, meat broth and in a food model (meat pieces. Acetic acid showed MIC and MFC of 0.6 and 1.25 µL.mL-1, respectively. For O. vulgare essential oil MIC and MBC were 1.25 and 2.5 µL.mL-1, respectively. FIC indexes of the mixture of essential oil and acetic acid at MIC x ½ were £ 1.0, showing an additive effect. No synergy was found at kill-time study. Anti-staphylococcal effect of the antimicrobials alone or in mixture (MIC x ½ was lower in meat than in nutrient and meat broths. The effective combination of essential oils and organic acids could appear as an attractive alternative for the food industry, as the doses to inhibit the microbial growth in foods can be lowered.Este estudo avaliou a ocorrência de um efeito inibitório potencializado quando da aplicação combinada do óleo essencial de O. vulgare e ácido acético sobre Staphylococcus aureus através da determinação Concentração Inibitória Fracional (FIC e de ensaios de tempo de morte em caldo nutriente, caldo base carne e em um modelo alimentar (pedaços de carne. O ácido acético mostrou um valor de CIM e CBM de 0,6 e 1,25 µL.mL-1, respectivamente. Estudos prévios encontraram valores de CIM e CBM para o óleo essencial de O. vulgare sobre as cepas teste de S. aureus de 1,25 e 1,5 µL.mL-1, respectivamente. Valores de índices de CIF da mistura do óleo essencial e ácido acético na concentração de CIM x ½ foram £ 1,0 caracterizando uma interação de adição. Nenhum efeito sinérgico foi encontrado nos ensaios de tempo de morte. O efeito anti-estafilocócico dos antimicrobianos isolados ou em combinação (CIM x ½ foi menor quando aplicado em carne em comparação a sua adição em

  18. Isolation, identification and characterization of regional indigenous Saccharomyces cerevisiae strains

    Science.gov (United States)

    Šuranská, Hana; Vránová, Dana; Omelková, Jiřina

    2016-01-01

    In the present work we isolated and identified various indigenous Saccharomyces cerevisiae strains and screened them for the selected oenological properties. These S. cerevisiae strains were isolated from berries and spontaneously fermented musts. The grape berries (Sauvignon blanc and Pinot noir) were grown under the integrated and organic mode of farming in the South Moravia (Czech Republic) wine region. Modern genotyping techniques such as PCR-fingerprinting and interdelta PCR typing were employed to differentiate among indigenous S. cerevisiae strains. This combination of the methods provides a rapid and relatively simple approach for identification of yeast of S. cerevisiae at strain level. In total, 120 isolates were identified and grouped by molecular approaches and 45 of the representative strains were tested for selected important oenological properties including ethanol, sulfur dioxide and osmotic stress tolerance, intensity of flocculation and desirable enzymatic activities. Their ability to produce and utilize acetic/malic acid was examined as well; in addition, H2S production as an undesirable property was screened. The oenological characteristics of indigenous isolates were compared to a commercially available S. cerevisiae BS6 strain, which is commonly used as the starter culture. Finally, some indigenous strains coming from organically treated grape berries were chosen for their promising oenological properties and these strains will be used as the starter culture, because application of a selected indigenous S. cerevisiae strain can enhance the regional character of the wines. PMID:26887243

  19. Cultivo da levedura Phaffia rhodozyma (Xanthophyllomyces dendrorhous em processo descontínuo alimentado para produção de astaxantina Cultivation of Phaffia rhodozyma (Xanthophyllomyces dendrorhous yeast in discontinuous system to obtain astaxanthin

    Directory of Open Access Journals (Sweden)

    Miriam Blümel Chociai

    2002-12-01

    Full Text Available A levedura Phaffia rhodozyma, produtora de astaxantina, pigmento carotenóide largamente empregado na aqüicultura de peixes e crustáceos, pode ser eficientemente cultivada num meio de cultura de baixo custo, à base de caldo de cana diluído 1:10 e uréia a 1 g/L. No entanto, a produção de biomassa e a formação do carotenóide sofrem a inibição pelo substrato (efeito "Crabtree", limitando desta forma a utilização do caldo de cana com concentrações da fonte de carbono superiores a 20 g/L, importante consideração na produção industrial de astaxantina. No presente trabalho, o cultivo da levedura P. rhodozyma foi realizado em processo descontínuo alimentado, no qual se obteve produtividade volumétrica de 0,024 mg astaxantina/L.h. em relação aos 0,013 mg astaxantina/L.h. obtidos no cultivo controle, que não sofreu alimentação da fonte de carbono.The yeast Phaffia rhodozyma produces astaxanthin, a carotenoid pigment widely applied in fish and crustaceous cultivation. This yeast can be efficiently cultured in a low cost medium, sugar cane broth diluted 1:10 and supplemented with 1 g/L urea. However, the biomass and astaxanthin production undergo inhibition by the substrate (Crabtree effect, limiting the utilization of sugar cane broth up to 20 g/L total sugar concentration. Therefore, this effect must be considered during the industrial production of astaxanthin. In the present work, using fed batch system to cultivate P. rhodozyma we were able to obtain 0.024 mg astaxanthin/l.h compared to 0.013 mg astaxanthin/l.h obtained by the discontinuous cultivation system.

  20. Tubos de látex: esterilidade pós-reprocessamento em vapor saturado sob pressão

    Directory of Open Access Journals (Sweden)

    Patrícia Staciarini Anders

    2009-06-01

    Full Text Available Entre os artigos odonto-médico-hospitalares, os tubulares merecem atenção especial para o reprocessamento peladificuldade de limpeza de seu lúmen, que pode permitir acúmulo de matéria orgânica e formação de biofilme. Com oobjetivo de avaliar a esterilidade dos tubos de látex submetidos ao processo de esterilização em autoclave a vapor emum hospital de Goiânia-GO foram analisados 30 tubos pós-reprocessamento. Realizaram-se cortes transversais de 01cm em dois segmentos dos tubos: extremidade (E e metade (M que foram inoculados em caldo BHI (Brain HeartInfusion e incubados a 37o C por 20 dias. Amostras com turvação visível foram semeadas em ágar sangue decarneiro para isolamento microbiano. As colônias desenvolvidas foram caracterizadas pela morfologia e por testesbioquímicos. Houve desenvolvimento microbiano em 05 (16,7% amostras, sendo 03 (10% segmentos M e 02(6,7% seguimentos E. Os microrganismos contaminantes foram identificados como bacilos Gram-positivo (BGP,estafilococos coagulase negativa e positiva (ECN, ECP. Múltiplos reprocessamentos desses artigos facilita o desgaste,colabamento, ressecamento, formação de rachaduras, o que favorece a retenção de microrganismos. De acordo comestes resultados, conclui-se que tubos de látex reprocessados em autoclave a vapor podem representar riscos aosusuários.

  1. The NADP+-dependent glutamate dehydrogenase of the yeast Kluyveromyces marxianus responds to nitrogen repression similarly to Saccharomyces cerevisiae Glutamato desidrogenase dependente de NADP+ da levedura Kluyveromyces marxianus responde à repressão catabólica de maneira similar à Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Marcos Antonio de Morais-Júnior

    2003-12-01

    Full Text Available NADP+-dependent glutamate dehydrogenase (NADP+-Gdh is the first step in ammonia assimilation pathway in Saccharomyces cerevisiae and the knowledge of its regulation is the key for many biotechnological purposes such as single cell protein production. The regulation of NADP+-Gdh activity in Kluyveromyces marxianus cells was evaluated under different ammonia supply in batch cultivations. The results showed that K. marxianus NADP+-Gdh activity is induced over a narrow range of extracellular ammonia supply, being repressed by both high ammonia concentration and the glutamate formed. This activity is not growth-associated and may function mainly to trace low amounts of ammonia after growth cessation. The results demonstrated that NADP+-Gdh may not be the main enzyme for ammonia assimilation in K. marxianus, as it has been postulated for K. lactis, instead is subjected to the same regulatory mechanism described for S. cerevisiae.Glutamato desidrogenase dependente de NADP+ (NADP+-Gdh constitui o primeiro passo enzimático no mecanismo de assimilação de nitrogênio em Saccharomyces cerevisiae e o conhecimento de sua regulação é chave na iniciativa de vários propósitos biotecnológicos, tais como a produção de proteína microbiana. A regulação da atividade NADP+-Gdh em células de Kluyveromyces marxianus foi avaliada a partir de diferentes condições de suprimento de amonia em cultivo em batelada. Os resultados mostraram que a atividade NADP+-Gdh de K. marxianus foi induzida em uma estreita faixa de concentração de amonia no meio, sendo reprimida tanto por altas concentrações deste composto quanto pelo produto glutamato. Esta atividade não está associada ao crescimento celular e deve funcionar principalmente no rastreamento de pequenas quantidades de amonia após a parada do crescimento celular. Isto demonstra que NADP+-Gdh não deve ser a principal enzima de assimilação de amonia em K. marxianus, como tem sido postulado para K

  2. Metabolic engineering of ammonium assimilation in xylose-fermenting Saccharomyes cerevisiae improves ethanol production

    DEFF Research Database (Denmark)

    Roca, Christophe Francois Aime; Nielsen, Jens; Olsson, Lisbeth

    2003-01-01

    Cofactor imbalance impedes xylose assimilation in Saccharomyces cerevisiae that has been metabolically engineered for xylose utilization. To improve cofactor use, we modified ammonia assimilation in recombinant S. cerevisiae by deleting GDH1, which encodes an NADPH-dependent glutamate dehydrogenase...

  3. Heterologous carotenoid production in Saccharomyces cerevisiae induces the pleiotropic drug resistance stress response

    NARCIS (Netherlands)

    Verwaal, R.; Jiang, Y.; Wang, J.; Daran, J.M.; Sandmann, G.; Berg, van den J.A.; Ooyen, van A.J.J.

    2010-01-01

    To obtain insight into the genome-wide transcriptional response of heterologous carotenoid production in Saccharomyces cerevisiae, the transcriptome of two different S. cerevisiae strains overexpressing carotenogenic genes from the yeast Xanthophyllomyces dendrorhous grown in carbon-limited chemosta

  4. Functional profiling of the Saccharomyces cerevisiae genome.

    Science.gov (United States)

    Giaever, Guri; Chu, Angela M; Ni, Li; Connelly, Carla; Riles, Linda; Véronneau, Steeve; Dow, Sally; Lucau-Danila, Ankuta; Anderson, Keith; André, Bruno; Arkin, Adam P; Astromoff, Anna; El-Bakkoury, Mohamed; Bangham, Rhonda; Benito, Rocio; Brachat, Sophie; Campanaro, Stefano; Curtiss, Matt; Davis, Karen; Deutschbauer, Adam; Entian, Karl-Dieter; Flaherty, Patrick; Foury, Francoise; Garfinkel, David J; Gerstein, Mark; Gotte, Deanna; Güldener, Ulrich; Hegemann, Johannes H; Hempel, Svenja; Herman, Zelek; Jaramillo, Daniel F; Kelly, Diane E; Kelly, Steven L; Kötter, Peter; LaBonte, Darlene; Lamb, David C; Lan, Ning; Liang, Hong; Liao, Hong; Liu, Lucy; Luo, Chuanyun; Lussier, Marc; Mao, Rong; Menard, Patrice; Ooi, Siew Loon; Revuelta, Jose L; Roberts, Christopher J; Rose, Matthias; Ross-Macdonald, Petra; Scherens, Bart; Schimmack, Greg; Shafer, Brenda; Shoemaker, Daniel D; Sookhai-Mahadeo, Sharon; Storms, Reginald K; Strathern, Jeffrey N; Valle, Giorgio; Voet, Marleen; Volckaert, Guido; Wang, Ching-yun; Ward, Teresa R; Wilhelmy, Julie; Winzeler, Elizabeth A; Yang, Yonghong; Yen, Grace; Youngman, Elaine; Yu, Kexin; Bussey, Howard; Boeke, Jef D; Snyder, Michael; Philippsen, Peter; Davis, Ronald W; Johnston, Mark

    2002-07-25

    Determining the effect of gene deletion is a fundamental approach to understanding gene function. Conventional genetic screens exhibit biases, and genes contributing to a phenotype are often missed. We systematically constructed a nearly complete collection of gene-deletion mutants (96% of annotated open reading frames, or ORFs) of the yeast Saccharomyces cerevisiae. DNA sequences dubbed 'molecular bar codes' uniquely identify each strain, enabling their growth to be analysed in parallel and the fitness contribution of each gene to be quantitatively assessed by hybridization to high-density oligonucleotide arrays. We show that previously known and new genes are necessary for optimal growth under six well-studied conditions: high salt, sorbitol, galactose, pH 8, minimal medium and nystatin treatment. Less than 7% of genes that exhibit a significant increase in messenger RNA expression are also required for optimal growth in four of the tested conditions. Our results validate the yeast gene-deletion collection as a valuable resource for functional genomics.

  5. Arsenate and phosphate interaction in Saccharomyces cerevisiae

    Institute of Scientific and Technical Information of China (English)

    GENG Chun-nu; ZHU Yong-guan

    2006-01-01

    In the present study, arsenate(As(Ⅴ)) and phosphate(P(Ⅴ)) interactions were investigated in growth, uptake and RNA content in yeast(Saccharomyces cerevisiae). Yeast grew slowly with As(Ⅴ) concentrations increasing in the medium. However, the maximal population density was almost the same among different As(Ⅴ) treatments. It was in the late log phase that yeast growth was augmented by low As(Ⅴ), which was maybe due to the fact that methionine metabolism was stressed by vitamin B6 deprivation, so As(Ⅴ)treatments did not affect maximal population density. However, with P (Ⅴ) concentrations increasing, the maximal population density increased. Therefore, the maximal population density was determined by P (Ⅴ) concentrations in the medium but not by As (Ⅴ)concentrations in the medium. Ycf1p(a tonoplast transpor) transports As(GS)3 into the vacuole, but arsenic(As) remaining in the thalli was 1.27% with As(Ⅴ) exposure for 60 h, from which it can be speculated that the percentage of As transported into vacuole should be lower than 1.27%. However, the percentage of As pumped out of cell was 71.49% with As (Ⅴ) exposure for 68 h. Although two pathways (extrusion and sequestration) were involved in As detoxification in yeast, the extrusion pathway played a major role in As detoxification. RNA content was the highest in the early-log phase and was reduced by As(Ⅴ).

  6. Acetylation dynamics and stoichiometry in Saccharomyces cerevisiae.

    Science.gov (United States)

    Weinert, Brian T; Iesmantavicius, Vytautas; Moustafa, Tarek; Schölz, Christian; Wagner, Sebastian A; Magnes, Christoph; Zechner, Rudolf; Choudhary, Chunaram

    2014-01-01

    Lysine acetylation is a frequently occurring posttranslational modification; however, little is known about the origin and regulation of most sites. Here we used quantitative mass spectrometry to analyze acetylation dynamics and stoichiometry in Saccharomyces cerevisiae. We found that acetylation accumulated in growth-arrested cells in a manner that depended on acetyl-CoA generation in distinct subcellular compartments. Mitochondrial acetylation levels correlated with acetyl-CoA concentration in vivo and acetyl-CoA acetylated lysine residues nonenzymatically in vitro. We developed a method to estimate acetylation stoichiometry and found that the vast majority of mitochondrial and cytoplasmic acetylation had a very low stoichiometry. However, mitochondrial acetylation occurred at a significantly higher basal level than cytoplasmic acetylation, consistent with the distinct acetylation dynamics and higher acetyl-CoA concentration in mitochondria. High stoichiometry acetylation occurred mostly on histones, proteins present in histone acetyltransferase and deacetylase complexes, and on transcription factors. These data show that a majority of acetylation occurs at very low levels in exponentially growing yeast and is uniformly affected by exposure to acetyl-CoA.

  7. Saccharomyces cerevisiae Is Permissive for Replication of Bovine Papillomavirus Type 1

    OpenAIRE

    Zhao, Kong-Nan; Frazer, Ian H

    2002-01-01

    We recently demonstrated that Saccharomyces cerevisiae protoplasts can take up bovine papillomavirus type 1 (BPV1) virions and that viral episomal DNA is replicated after uptake. Here we demonstrate that BPV virus-like particles are assembled in infected S. cerevisiae cultures from newly synthesized capsid proteins and also package newly synthesized DNA, including full-length and truncated viral DNA and S. cerevisiae-derived DNA. Virus particles prepared in S. cerevisiae are able to convey pa...

  8. Determinação de isotermas de adsorção de Saccharomyces cerevisiae empregando acetato e sulfato de cádmio Cadmium adsorption isotherms by Saccharomyces cerevisiae using cadmiun acetate and sulphate

    Directory of Open Access Journals (Sweden)

    Silvana Albertini

    2007-06-01

    Full Text Available Para determinar as isotermas de adsorção de cádmio por Saccharomyces cerevisiae, foram utilizados os sais acetato e sulfato de cádmio, nas concentrações de 5; 10; 20; 40; 60; 80 e 100 mg.L-1. A biomassa foi produzida a partir de uma cultura "starter" de Saccharomyces cerevisiae IZ 1904. Após o contato de 16 horas entre o microrganismo em estudo e as soluções teste, a biomassa foi separada por centrifugação e o teor de cádmio residual foi determinado por espectrofotometria de absorção atômica diretamente no sobrenadante. Os dois sais testados demonstraram acúmulo crescente do metal nas concentrações de 5; 10; 20 e 40 mg.L-1. Porém, nas concentrações de 60; 80 e 100 mg.L-1, foi observado um acúmulo decrescente do metal, mostrando assim danos da parede celular, nem sempre evidenciados em nível de membrana citoplasmática, visualizados por microscopia eletrônica de varredura.To determine the isotherms of the adsorption of cadmium for Saccharomyces cerevisiae, acetate and sulphate salts were used at the concentrations of 5, 10, 20, 40, 60, 80, and 100 mg.L-1. The biomass was produced from a starter culture of Saccharomyces cerevisiae IZ 1904. After the contact of 16 hours among the microrganism study and the solution-test, the biomass was separated by a centrifugation and the cadmium residue content was determined directly in the supernatant by atomic absorption spectrophotometry. For the two salts which were used, a growing accumulation of cadmium was observed at concentrations of 5, 10, 20, and 40 mg.L-1. In the concentrations of 60; 80 and 100 mg.L-1 a decrease in the accumulation of the metal was observed, showing damage to the cellular wall, not always observed at the membrane citoplasmatic's level, visualized by a scanning electron microscopy.

  9. Ultrastructural changes of Saccharomyces cerevisiae in response to ethanol stress.

    Science.gov (United States)

    Ma, Manli; Han, Pei; Zhang, Ruimin; Li, Hao

    2013-09-01

    In the fermentative process using Saccharomyces cerevisiae to produce bioethanol, the performance of cells is often compromised by the accumulation of ethanol. However, the mechanism of how S. cerevisiae responds against ethanol stress remains elusive. In the current study, S. cerevisiae cells were cultured in YPD (yeast extract - peptone - dextrose) medium containing various concentrations of ethanol (0%, 2.5%, 5%, 7.5%, 10%, and 15% (v/v)). Compared with the control group without ethanol, the mean cell volume of S. cerevisiae decreased significantly in the presence of 7.5% and 10% ethanol after incubation for 16 h (P < 0.05), and in the presence of 15% ethanol at all 3 sampling time points (1, 8, and 16 h) (P < 0.05). The exposure of S. cerevisiae cells to ethanol also led to an increase in malonyldialdehyde content (P < 0.05) and a decrease in sulfhydryl group content (P < 0.05). Moreover, the observations through transmission electron microscopy enabled us to relate ultrastructural changes elicited by ethanol with the cellular stress physiology. Under ethanol stress, the integrity of the cell membrane was compromised. The swelling or distortion of mitochondria together with the occurrence of a single and large vacuole was correlated with the addition of ethanol. These results suggested that the cell membrane is one of the targets of ethanol, and the degeneration of mitochondria promoted the accumulation of intracellular reactive oxygen species.

  10. Removing cadmium from electroplating wastewater by waste saccharomyces cerevisiae

    Institute of Scientific and Technical Information of China (English)

    DAI Shu-juan; WEI De-zhou; ZHOU Dong-qin; JIA Chun-yun; WANG Yu-juan; LIU Wen-gang

    2008-01-01

    The appropriate condition and scheme of removing cadmium from electroplating wastewater were investigated by adsorption-precipitation method using waste saccharomyces cerevisiae(WSC) as sorbent. Effect factors on biosorption of cadmium in cadmium-containing electroplating wastewater by waste saccharomyces cerevisiae and precipitation process of waste saccharomyces cerevisiae after adsorbing cadmium were studied. The results show that removal rate of cadmium is over 88% after 30 min adsorbing under the condition of cadmium concentration 26 mg/L, the dosage of waste saccharomyces cerevisiae 16.25 g/L, temperature 18 ℃, pH 6.0 and precipitation time 4 h. Biosorption-precipitation method is effective to remove cadmium in cadmium-containing electroplating wastewater by waste saccharomyces cerevisiae. The SEM, infrared spectroscopy and Zeta-potential of the cells show that chemical chelating is the main adsorption form; electrostatic attraction, hydrogen bonding and van der Waals force all function in adsorption process; and ―NH2―,―C=O―,―C=O―NH―,―CH3, ―OH are the main adsorption groups.

  11. Saccharomyces cerevisiae as a starter culture in Mycella.

    Science.gov (United States)

    Hansen, T K; Tempel, T V; Cantor, M D; Jakobsen, M

    2001-09-19

    The potential use of Saccharomyces cerevisiae FB7 as an additional starter culture for the production of Mycella, a Danish Gorgonzola type cheese, was investigated. Two dairy productions of Mycella, each containing batches of experimental cheeses with S. cerevisiae added and reference cheeses without yeast added were carried out. For both experimental and reference cheeses, chemical analysis (pH, a(w), NaCl, water and fat content) were carried out during the ripening period, but no significant differences were found. The evolution of lactic acid bacteria was almost identical in both the experimental and reference cheeses and similar results were found for the number of yeast. S. cerevisiae FB7 was found to be predominant in the core of the experimental cheeses throughout the ripening period, while Debaryomyces hansenii dominated in the reference cheese and on the surface of the experimental cheeses. In the cheeses with S. cerevisiae FB7, an earlier sporulation and an improved growth of Penicillium roqueforti was observed compared to the reference cheeses. Furthermore, in the experimental cheese, synergistic interactions were also found in the aroma analysis, the degradation of casein and by the sensory analysis. The observed differences indicate a positive contribution to the overall quality of Mycella by S. cerevisiae FB7.

  12. Genetic mapping of quantitative phenotypic traits in Saccharomyces cerevisiae.

    Science.gov (United States)

    Swinnen, Steve; Thevelein, Johan M; Nevoigt, Elke

    2012-03-01

    Saccharomyces cerevisiae has become a favorite production organism in industrial biotechnology presenting new challenges to yeast engineers in terms of introducing advantageous traits such as stress tolerances. Exploring subspecies diversity of S. cerevisiae has identified strains that bear industrially relevant phenotypic traits. Provided that the genetic basis of such phenotypic traits can be identified inverse engineering allows the targeted modification of production strains. Most phenotypic traits of interest in S. cerevisiae strains are quantitative, meaning that they are controlled by multiple genetic loci referred to as quantitative trait loci (QTL). A straightforward approach to identify the genetic basis of quantitative traits is QTL mapping which aims at the allocation of the genetic determinants to regions in the genome. The application of high-density oligonucleotide arrays and whole-genome re-sequencing to detect genetic variations between strains has facilitated the detection of large numbers of molecular markers thus allowing high-resolution QTL mapping over the entire genome. This review focuses on the basic principle and state of the art of QTL mapping in S. cerevisiae. Furthermore we discuss several approaches developed during the last decade that allow down-scaling of the regions identified by QTL mapping to the gene level. We also emphasize the particular challenges of QTL mapping in nonlaboratory strains of S. cerevisiae.

  13. ACÚMULO DE CÁDMIO POR Saccharomyces cerevisiae FERMENTANDO MOSTO DE MELAÇO

    Directory of Open Access Journals (Sweden)

    L.G. do PRADO-FILHO

    1998-01-01

    Full Text Available O presente trabalho visou o estudo do acúmulo de cádmio (Cd por Saccharomyces cerevisiae, fermentando mosto de melaço com contaminações controladas em níveis sub-tóxicos do citado metal. As condições de fermentação foram similares às reinantes na produção industrial de etanol. O mosto, não esterilizado, continha 12% de açúcares redutores totais (ART e pH 4,5. Para a contaminação controlada empregou-se dois sais de cádmio, cloreto e acetato e, quatro níveis de contaminação 0,5; 1,0; 2,0 e 5,0 mg Cd.kg-1 mosto. A inoculação do mosto foi executada com fermento de panificação (10% p/p. Após a fermentação (4 horas foram determinados, porcentagem de fermento no vinho centrifugado e teor alcoólico. Na levedura separada foram determinados peso úmido, matéria seca, proteína bruta e teores de cádmio por espectrofotometria de absorção atômica. Em todos os níveis de contaminação estudados houve acúmulo de Cd pela levedura e diminuição do rendimento em etanol.The aim of this paper was to study the cadmium (Cd accumulation by Saccharomyces cerevisiae fermenting wort of molasses, under sub-toxic levels of controlled cadmium contamination. Fermentation conditions were similar to industrial alcohol production. Non-sterelized wort had 12% of total reducing sugars (w/w and pH 4.5. For the controlled contamination, two cadmium salts were used (chloride and acetate, at four levels of contamination: 0.5; 1.0; 2.0 and 5.0 mg Cd.kg-1 wort. The inoculation of the wort was carried out with commercial bread yeast (10% w/w. After fermentation (4 hours, samples were evaluated for cellular viability, alcohol content and yeast percentage in the centrifuged wine. The centrifuged yeast cells were evaluated for total fresh and dry weight, total protein, and cadmium concentration by atomic absortion spectroscopy. In all Cd levels, there was cadmium accumulation by yeast and a decrease in ethanol yield.

  14. An apoptotic cell cycle mutant in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Villadsen, Ingrid

    1996-01-01

    The simple eukaryote Saccharomyces cerevisiae has proved to be a useful organism for elucidating the mechanisms that govern cell cycle progression in eukaryotic cells. The excellent in vivo system permits a cell cycle study using temperature sensitive mutants. In addition, it is possible to study...... many genes and gene products from higher eukaryotes in Saccharomyces cerevisiae because many genes and biological processes are homologous or similar in lower and in higher eukaryotes. The highly developed methods of genetics and molecular biology greatly facilitates studies of higher eukaryotic...... processes.Programmmed cell death with apoptosis plays a major role in development and homeostatis in most, if not all, animal cells. Apoptosis is a morphologically distinct form of death, that requires the activation of a highly regulated suicide program. Saccharomyces cerevisiae provides a new system...

  15. Functional expression and evaluation of heterologous phosphoketolases in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Bergman, Alexandra; Siewers, Verena; Nielsen, Jens;

    2016-01-01

    Phosphoketolases catalyze an energy-and redox-independent cleavage of certain sugar phosphates. Hereby, the two-carbon (C2) compound acetyl-phosphate is formed, which enzymatically can be converted into acetyl-CoA-a key precursor in central carbon metabolism. Saccharomyces cerevisiae does...... C5 and C6 sugars towards C2-synthesis. Nine phosphoketolase candidates were expressed in S. cerevisiae of which seven produced significant amounts of acetyl-phosphate after provision of sugar phosphate substrates in vitro. The candidates showed differing substrate specificities, and some...... demonstrated activity levels significantly exceeding those of candidates previously expressed in yeast. The conducted studies also revealed that S. cerevisiae contains endogenous enzymes capable of breaking down acetyl-phosphate, likely into acetate, and that removal of the phosphatases Gpp1 and Gpp2 could...

  16. Metabolic engineering of Saccharomyces cerevisiae for lactose/whey fermentation.

    Science.gov (United States)

    Domingues, Lucília; Guimarães, Pedro M R; Oliveira, Carla

    2010-01-01

    Lactose is an interesting carbon source for the production of several bio-products by fermentation, primarily because it is the major component of cheese whey, the main by-product of dairy activities. However, the microorganism more widely used in industrial fermentation processes, the yeast Saccharomyces cerevisiae, does not have a lactose metabolization system. Therefore, several metabolic engineering approaches have been used to construct lactose-consuming S. cerevisiae strains, particularly involving the expression of the lactose genes of the phylogenetically related yeast Kluyveromyces lactis, but also the lactose genes from Escherichia coli and Aspergillus niger, as reviewed here. Due to the existing large amounts of whey, the production of bio-ethanol from lactose by engineered S. cerevisiae has been considered as a possible route for whey surplus. Emphasis is given in the present review on strain improvement for lactose-to-ethanol bioprocesses, namely flocculent yeast strains for continuous high-cell-density systems with enhanced ethanol productivity.

  17. Effect of lactic acid bacteria on extention of shelf life and growth of Listeria monocytogenes in beef steaks stored in CO2- rich atmosphere Efeito de bactérias láticas na extensâo da vida de parateleira e multiplicação de Listeria monocytogenes em fatias de carne bovina armazenadas em atmosfera rica em CO2

    Directory of Open Access Journals (Sweden)

    Djamel Djenane

    2005-12-01

    monocytogenes em caldo foi inibida por bactérias isoladas da superfície das carnes inoculadas com as bactérias láticas. Após 7 dias a 3ºC, a contagem inicial de L. monocytogenes de 5.6 log UFC.mL-1 caiu para 2.8 log UFC.mL-1 na ausência de bactéria lática protetora. A 8ºC, as contagens de L. monocytogenes foram reduzidas em 2.5 ou 1.5 log na presença de Lb. sakei CTC 372 ou Lb. CTC 711, respectivamente. A 25ºC, as contagens de L. monocytogenes no caldo contendo uma das bactérias láticas protetoras foram 5 log mais baixas do que nos caldos contendo L. monocytogenes somente.

  18. Understanding the 3-hydroxypropionic acid tolerance mechanism in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Kildegaard, Kanchana Rueksomtawin; Juncker, Agnieszka; Hallstrom, Bjorn;

    2013-01-01

    a sustainable alternative for production of acrylic acid from renewable feedstocks. We are establishing Saccharomyces cerevisiae as an alternative host for 3HP production. However, 3HP also inhibits yeast grow th at level well below what is desired for commercial applications. Therefore, we are aiming...... to improve 3HP tolerance in S. cerevisiae by applying adaptive evolution approach. We have generated yeast strains with sign ificantly improved capacity for tolerating 3HP when compared to the wild-type. We will present physiolo gical characterization, genome re-sequencing, and transcriptome analysis...

  19. Expression and secretion of Aspergillus niger glucoamylase in Saccharomyces cerevisiae

    Institute of Scientific and Technical Information of China (English)

    李文清; 何鸣; 罗进贤

    1995-01-01

    Aspergillus niger glucoamylase GA 1 cDNA was inserted in between the yeast PGK promoter and terminator on plasmid pMA91. The resultant plasmid pMAG69 was introduced into Saccharomyces cerevisiae GRF18 by protoplast transformation. The A niger GA I cDNA was expressed efficiently under the contiol of PGK promoter and 99% of the gene products were secreted into the culture medium using its own signal sequence The recombmant yeast can digest 87% of starch in 2 d in the medium containing 10% starch. The recombinant plasmid pMAG69 can exist stably in 5. cerevisiae.

  20. Genetic mapping of Ty elements in Saccharomyces cerevisiae.

    OpenAIRE

    Klein, H L; Petes, T. D.

    1984-01-01

    We used transformation to insert a selectable marker at various sites in the Saccharomyces cerevisiae genome occupied by the transposable element Ty. The vector CV9 contains the LEU2+ gene and a portion of the repeated element Ty1-17. Transformation with this plasmid resulted in integration of the vector via a reciprocal exchange using homology at the LEU2 locus or at the various Ty elements that are dispersed throughout the S. cerevisiae genome. These transformants were used to map genetical...

  1. Saccharomyces cerevisiae como probiótico para alevinos de tilápia-do-nilo submetidos a desafio sanitário Saccharomyces cerevisiae as probiotic for Nile tilapia fingerlings submitted to a sanitary challenge

    Directory of Open Access Journals (Sweden)

    Fábio Meurer

    2007-10-01

    Full Text Available Este experimento foi realizado com o objetivo de avaliar a utilização de levedura Saccharomyces cerevisiae (SC como probiótico em rações para alevinos de tilápia-do-nilo (Oreochromis niloticus submetidos a desafio sanitário. Foram utilizados 60 alevinos com 30 dias de idade, pesando 0,45 ± 0,02 g e medindo 3,10 ± 0,14 cm, distribuídos em delineamento completamente casualizado com dois tratamentos e seis repetições em 12 aquários de 50 L. Como desafio sanitário, cada aquário recebeu diariamente, durante o período experimental, o equivalente a 0,5 mL de esterco suíno in natura. Os tratamentos consistiram de uma ração com (0,1% SC e sem probiótico. Ao final do experimento, os alevinos foram contados, medidos e pesados. Foram também retirados e pesados os intestinos de dois alevinos de cada tratamento, escolhidos aleatoriamente. O conteúdo dos intestinos foi submetido à contagem do número de bactérias e coliformes totais presentes. O desempenho e a sobrevivência não foram influenciados pela inclusão de SC na dieta. A SC colonizou o intestino dos alevinos alimentados com a dieta com SC e não foi encontrada naqueles alimentados com a dieta sem probiótico. Não foram observadas diferenças no número de bactérias e coliformes totais por grama de conteúdo intestinal e por mL de água dos aquários. A utilização de Saccharomyces cerevisiae como probiótico em rações para alevinos de tilápia-do-nilo (Oreochromis niloticus promoveu a colonização no intestino dos peixes, entretanto, não influenciou o desempenho produtivo e a sobrevivência em sistema de cultivo com desafio sanitário.The present experiment was carried with the objective to evaluate the Saccharomyces cerevisiae (SC as probiotic in rations for Nile tilapia (Oreochromis niloticus fingerlings submitted to a sanitary challenge. A total of 60 fingerlings with 30 days old, weighing 0.45 ± 0.02 g and 3.10 ± 0.14 cm were distributed to a completely

  2. UTILIZAÇÃO DA CIANOBACTÉRIA Spirulina maxima E DA LEVEDURA Saccharomyces cerevisiae COMO DIETAS COMPLEMENTARES NO CULTIVO DE Artemia franciscana

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    Ivanildo Surini de Souza

    2015-07-01

    Full Text Available Diferentes combinações da cianobactéria S. maxima e da levedura S. cerevisiae foram utilizadas no cultivo de A. franciscana, com o objetivo de avaliar dietas de baixo custo e fácil manuseio, e que mantivessem as larvas desse microcrustáceo em laboratório, de modo a propiciar estudos de sua ecologia, biologia e uso na aquicultura. Para isso, 12 cones de Imhoff contendo 1 L de água do mar filtrada foram estocados com 100 náuplios e submetidos à aeração contínua, monitoramento do pH, temperatura, salinidade, oxigênio dissolvido e luminosidade, além de renovação diária de 50 % do volume de água. Durante dez dias, os náuplios foram alimentados duas vezes ao dia com 25 mg de diferentes combinações de S. maxima e S. cerevisiae, nas seguintes proporções: 100/0; 75/25; 50/50; 25/75 e 0/100. Foram avaliadas a taxa de sobrevivência, proporção sexual, proporção juvenis/adultos e performance reprodutiva. Os resultados indicaram um melhor desempenho zootécnico de A. franciscana nos tratamentos que associaram S. maxima à S. cerevisiae (75/25, 50/50 e 25/75, e desta maneira, demonstram que a referida mistura dietética, em tais proporções, é viável para manter as larvas em cultivo laboratorial.

  3. Bacteriocin like substance production by Carnobacterium piscicola in a continuous system with three culture broths. Study of antagonism against Listeria monocytogenes on vacuum packaged salmon Produção de substâncias semelhantes à bacteriocinas por C. piscicola em um sistema contínuo com três meios de cultura e seu antagonismo contra L. monocytogenes em salmão embalado a vácuo

    Directory of Open Access Journals (Sweden)

    Renate P. Schöbitz

    2006-03-01

    verificado a cada 5 dias, durante 15 dias. C. piscicola L 103 antigiu a fase estacionária depois de 12 h de incubação em cultivo em batelada, sendo a atividade SSB de 800 AU mL-1 nos meios D-MRS e mod. D-MRS e de 400 AU mL-1 no caldo APT. Durante a cultura continua, a atividade SSB aumentou até 6400 AU mL-1 nos dois tipos de caldo MRS, ao passo que no caldo APT esta atividade diminuiu a 50 AU mL-1, indicando uma clara vantagem de uso dos dois primeiros meios de cultura e do sistema de crescimento contínuo. SSB mostrou efeito bacteriostático sobre L. monocytogenes quando inoculada em salmão, com contagens de 6,0 x 10³ ufc cm-2 após 15 dias. Não foram encontradas diferenças significantes entre as duas atividades utilizadas. No ensaio controle, sem SSB, a contagem de L. monocytogenes aumentou até 1,0 x 10(6 ufc cm-2 após 15 dias de estocagem.

  4. Interaction between Hanseniaspora uvarum and Saccharomyces cerevisiae during alcoholic fermentation.

    Science.gov (United States)

    Wang, Chunxiao; Mas, Albert; Esteve-Zarzoso, Braulio

    2015-08-03

    During wine fermentation, Saccharomyces clearly dominate over non-Saccharomyces wine yeasts, and several factors could be related to this dominance. However, the main factor causing the reduction of cultivable non-Saccharomyces populations has not yet been fully established. In the present study, various single and mixed fermentations were performed to evaluate some of the factors likely responsible for the interaction between Saccharomyces cerevisiae and Hanseniaspora uvarum. Alcoholic fermentation was performed in compartmented experimental set ups with ratios of 1:1 and 1:9 and the cultivable population of both species was followed. The cultivable H. uvarum population decreased sharply at late stages when S. cerevisiae was present in the other compartment, similarly to alcoholic fermentations in non-compartmented vessels. Thus, cell-to-cell contact did not seem to be the main cause for the lack of cultivability of H. uvarum. Other compounds related to fermentation performance (such as sugar and ethanol) and/or certain metabolites secreted by S. cerevisiae could be related to the sharp decrease in H. uvarum cultivability. When these factors were analyzed, it was confirmed that metabolites from S. cerevisiae induced lack of cultivability in H. uvarum, however ethanol and other possible compounds did not seem to induce this effect but played some role during the process. This study contributes to a new understanding of the lack of cultivability of H. uvarum populations during the late stages of wine fermentation.

  5. Recycling carbon dioxide during xylose fermentation by engineered Saccharomyces cerevisiae

    Science.gov (United States)

    In this study, we introduced the ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) and phosphoribulokinase (PRK) into an engineered S. cerevisiae (SR8) harboring the XR/XDH pathway and up-regulated PPP 10, to enable CO2 recycling through a synthetic rPPP during xylose fermentation (Fig. 1). ...

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

    Science.gov (United States)

    Deutch, Charles E.; Marshall, Pamela A.

    2008-01-01

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

  7. The enantioselective b-keto ester reductions by Saccharomyces cerevisiae

    OpenAIRE

    HASSAN TAJIK; KHALIL TABATABAEIAN; MAHMOOD SHAHBAZI

    2006-01-01

    The enantioselective yeast reduction of aromatic b-keto esters, by use of potassium dihydrogen phosphate, calcium phosphate (monobasic), magnesium sulfate and ammonium tartrate (diammonium salt) (10:1:1:50) in water at pH 7 as a buffer for 72–120 h with 45–90 % conversion to the corresponding aromatic -hydroxy esters was achieved by means of Saccharomyces cerevisiae.

  8. Sucrose and Saccharomyces cerevisiae: a relationship most sweet.

    Science.gov (United States)

    Marques, Wesley Leoricy; Raghavendran, Vijayendran; Stambuk, Boris Ugarte; Gombert, Andreas Karoly

    2016-02-01

    Sucrose is an abundant, readily available and inexpensive substrate for industrial biotechnology processes and its use is demonstrated with much success in the production of fuel ethanol in Brazil. Saccharomyces cerevisiae, which naturally evolved to efficiently consume sugars such as sucrose, is one of the most important cell factories due to its robustness, stress tolerance, genetic accessibility, simple nutrient requirements and long history as an industrial workhorse. This minireview is focused on sucrose metabolism in S. cerevisiae, a rather unexplored subject in the scientific literature. An analysis of sucrose availability in nature and yeast sugar metabolism was performed, in order to understand the molecular background that makes S. cerevisiae consume this sugar efficiently. A historical overview on the use of sucrose and S. cerevisiae by humans is also presented considering sugarcane and sugarbeet as the main sources of this carbohydrate. Physiological aspects of sucrose consumption are compared with those concerning other economically relevant sugars. Also, metabolic engineering efforts to alter sucrose catabolism are presented in a chronological manner. In spite of its extensive use in yeast-based industries, a lot of basic and applied research on sucrose metabolism is imperative, mainly in fields such as genetics, physiology and metabolic engineering.

  9. Adsorption and Interfacial Electron Transfer of Saccharomyces Cerevisiae

    DEFF Research Database (Denmark)

    Hansen, Allan Glargaard; Boisen, Anja; Nielsen, Jens Ulrik;

    2003-01-01

    We have studied the adsorption and electron-transfer dynamics of Saccharomyces cerevisiae (yeast) iso-l-cytochrome c adsorbed on Au(lll) electrodes in aqueous phosphate buffer media. This cytochrome possesses a thiol group dos e to the protein surface (Cysl02) suitable for linking the protein...

  10. 2μ plasmid in Saccharomyces species and in Saccharomyces cerevisiae.

    Science.gov (United States)

    Strope, Pooja K; Kozmin, Stanislav G; Skelly, Daniel A; Magwene, Paul M; Dietrich, Fred S; McCusker, John H

    2015-12-01

    We determined that extrachromosomal 2μ plasmid was present in 67 of the Saccharomyces cerevisiae 100-genome strains; in addition to variation in the size and copy number of 2μ, we identified three distinct classes of 2μ. We identified 2μ presence/absence and class associations with populations, clinical origin and nuclear genotypes. We also screened genome sequences of S. paradoxus, S. kudriavzevii, S. uvarum, S. eubayanus, S. mikatae, S. arboricolus and S. bayanus strains for both integrated and extrachromosomal 2μ. Similar to S. cerevisiae, we found no integrated 2μ sequences in any S. paradoxus strains. However, we identified part of 2μ integrated into the genomes of some S. uvarum, S. kudriavzevii, S. mikatae and S. bayanus strains, which were distinct from each other and from all extrachromosomal 2μ. We identified extrachromosomal 2μ in one S. paradoxus, one S. eubayanus, two S. bayanus and 13 S. uvarum strains. The extrachromosomal 2μ in S. paradoxus, S. eubayanus and S. cerevisiae were distinct from each other. In contrast, the extrachromosomal 2μ in S. bayanus and S. uvarum strains were identical with each other and with one of the three classes of S. cerevisiae 2μ, consistent with interspecific transfer.

  11. Reconstitution of an efficient thymidine salvage pathway in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Vernis, L.; Piskur, Jure; Diffley, J.F.X.

    2003-01-01

    The budding yeast Saccharomyces cerevisiae is unable to incorporate exogenous nucleosides into DNA. We have made a number of improvements to existing strategies to reconstitute an efficient thymidine salvage pathway in yeast. We have constructed strains that express both a nucleoside kinase as well...

  12. The Plasma Membrane of Saccharomyces cerevisiae : Structure, Function, and Biogenesis

    NARCIS (Netherlands)

    VANDERREST, ME; KAMMINGA, AH; NAKANO, A; ANRAKU, Y; POOLMAN, B; KONINGS, WN

    1995-01-01

    The composition of phospholipids, sphingolipids, and sterols in the plasma membrane has a strong influence on the activity of the proteins associated or embedded in the lipid bilayer. Since most lipid-synthesizing enzymes in Saccharomyces cerevisiae are located in intracellular organelles, an extens

  13. Reducing the genetic complexity of glycolysis in Saccharomyces cerevisiae

    NARCIS (Netherlands)

    Solis Escalante, D.

    2015-01-01

    Glycolysis, a biochemical pathway that oxidizes glucose to pyruvate, is at the core of sugar metabolism in Saccharomyces cerevisiae (bakers’ yeast). Glycolysis is not only a catabolic route involved in energy conservation, but also provides building blocks for anabolism. From an applied perspective,

  14. Diferentes condimentos vegetais: avaliação sensorial e de atividade antibacteriana em preparação alimentar com frango cozido Different spice plants: sensorial evaluation and antibacterial activity in chicken broth

    Directory of Open Access Journals (Sweden)

    F. Rodrigues

    2011-01-01

    Full Text Available A partir da atividade antibacteriana in vitro, predeterminada em doze plantas com indicativo etnográfico condimentar, testou-se este atributo in loco no modelo caldo com frango cozido. Primeiramente, procedeu-se ao treinamento de 10 avaliadores, segundo a legislação vigente quanto ao Consentimento Livre e Esclarecido, oportunizando conhecimentos prévios sobre as plantas salsa (Petroselinum sativum, manjerona branca (Origanum X aplii, manjerona preta (Origanum majorana, manjericão (Ocimum basilicum, sálvia (Salvia officinalis, tomilho (Thymus vulgaris, anis verde (Ocimum selloi, alfavaca (Ocimum gratissimum, alho nirá (Allium tuberosum, alho poró (Allium porrum, cúrcuma (Curcuma longa e pimenta dedo-de-moça (Capsicum baccatum. Realizou-se, através da adição individualizada desses condimentos ao caldo com frango cozido, um Teste de Aceitação tipo escala hedônica, selecionando, dentre os doze condimentos, quatro deles que se destacaram sensorialmente, a pimenta dedo-de-moça, o alho nirá, o alho poró e o tomilho. Foi feito, então, um Teste de Aceitação de concentrações denominadas pequena, média e grande destes quatro condimentos, para determinação da intensidade sensorialmente melhor aceita. As quantidades eleitas (0,5 g de pimenta dedo-de-moça, 15 g de alho nirá, 15 g de alho poró e 5 g de tomilho foram acrescidas ao caldo com frango cozido, sendo estes desafiados frente a Escherichia coli (ATCC 11229 em concentração final de 10 UFC mL-1, limite tolerado pela legislação, tendo como grupo-controle o caldo com frango cozido sem condimentos. O crescimento bacteriano foi aferido a cada duas horas após a inoculação, até completar 24 horas de confronto, utilizando-se meio seletivo para coliformes termo-resistentes e incubação constante a 25ºC em DBO, sendo atribuídos valores arbitrários às variações logarítmicas de crescimento. Comparados ao controle, todos os tratamentos condimentados apresentaram

  15. Saccharomyces cerevisiae as a model organism: a comparative study.

    Directory of Open Access Journals (Sweden)

    Hiren Karathia

    Full Text Available BACKGROUND: Model organisms are used for research because they provide a framework on which to develop and optimize methods that facilitate and standardize analysis. Such organisms should be representative of the living beings for which they are to serve as proxy. However, in practice, a model organism is often selected ad hoc, and without considering its representativeness, because a systematic and rational method to include this consideration in the selection process is still lacking. METHODOLOGY/PRINCIPAL FINDINGS: In this work we propose such a method and apply it in a pilot study of strengths and limitations of Saccharomyces cerevisiae as a model organism. The method relies on the functional classification of proteins into different biological pathways and processes and on full proteome comparisons between the putative model organism and other organisms for which we would like to extrapolate results. Here we compare S. cerevisiae to 704 other organisms from various phyla. For each organism, our results identify the pathways and processes for which S. cerevisiae is predicted to be a good model to extrapolate from. We find that animals in general and Homo sapiens in particular are some of the non-fungal organisms for which S. cerevisiae is likely to be a good model in which to study a significant fraction of common biological processes. We validate our approach by correctly predicting which organisms are phenotypically more distant from S. cerevisiae with respect to several different biological processes. CONCLUSIONS/SIGNIFICANCE: The method we propose could be used to choose appropriate substitute model organisms for the study of biological processes in other species that are harder to study. For example, one could identify appropriate models to study either pathologies in humans or specific biological processes in species with a long development time, such as plants.

  16. Enhanced lysosomal activity by overexpressed aminopeptidase Y in Saccharomyces cerevisiae.

    Science.gov (United States)

    Yoon, Jihee; Sekhon, Simranjeet Singh; Kim, Yang-Hoon; Min, Jiho

    2016-06-01

    Saccharomyces cerevisiae contains vacuoles corresponding to lysosomes in higher eukaryotes. Lysosomes are dynamic (not silent) organelles in which enzymes can be easily integrated or released when exposed to stressful conditions. Changes in lysosomal enzymes have been observed due to oxidative stress, resulting in an increased function of lysosomes. The protein profiles from H2O2- and NH4Cl-treated lysosomes showed different expression patterns, observed with two-dimensional gel electrophoresis. The aminopeptidase Y protein (APE3) that conspicuously enhanced antimicrobial activity than other proteins was selected for further studies. The S. cerevisiae APE3 gene was isolated and inserted into pYES2.0 expression vector. The GFP gene was inserted downstream to the APE3 gene for confirmation of APE3 targeting to lysosomes, and S. cerevisiae was transformed to pYES2::APE3::GFP. The APE3 did not enter in lysosomes and formed an inclusion body at 30 °C, but it inserted to lysosomes as shown by the merger of GFP with lysosomes at 28 °C. Antimicrobial activity of the cloned S. cerevisiae increased about 5 to 10 % against eight strains, compared to normal cells, and galactose induction is increased more two folds than that of normal cells. Therefore, S. cerevisiae was transformed to pYES2::APE3::GFP, accumulating a large amount of APE3, resulting in increased lysosomal activity. Increase in endogenous levels of lysosomes and their activity following genetic modification can lead to its use in applications such as antimicrobial agents and apoptosis-inducing materials for cancer cells, and consequently, it may also be possible to use the organelles for improving in vitro functions.

  17. [Saccharomyces cerevisiae as a model organism for studying the carcinogenicity of non-ionizing electromagnetic fields and radiation].

    Science.gov (United States)

    Voĭchuk, S I

    2014-01-01

    Medical and biological aspects of the effects of non-ionizing electromagnetic (EM) fields and radiation on human health are the important issues that have arisen as a result of anthropogenic impact on the biosphere. Safe use of man-made sources of non-ionizing electromagnetic fields and radiation in a broad range of frequencies--static, radio-frequency and microwave--is a subject of discussions and speculations. The main problem is the lack of understanding of the mechanism(s) of reception of EMFs by living organisms. In this review we have analyzed the existing literature data regarding the effects of the electromagnetic radiation on the model eukaryotic organism--yeast Saccharomyces cerevisiae. An attempt was made to estimate the probability of induction of carcinogenesis in humans under the influence of magnetic fields and electromagnetic radiation of extremely low frequency, radio frequency and microwave ranges.

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

    Directory of Open Access Journals (Sweden)

    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.

  19. Reference Gene Selection in the Desert Plant <em>Eremosparton songoricuem>m>

    Directory of Open Access Journals (Sweden)

    Dao-Yuan Zhang

    2012-06-01

    Full Text Available <em>Eremosparton songoricum em>(Litv. Vass. (<em>E. songoricumem> is a rare and extremely drought-tolerant desert plant that holds promise as a model organism for the identification of genes associated with water deficit stress. Here, we cloned and evaluated the expression of eight candidate reference genes using quantitative real-time reverse transcriptase polymerase chain reactions. The expression of these candidate reference genes was analyzed in a diverse set of 20 samples including various <em>E. songoricumem> plant tissues exposed to multiple environmental stresses. GeNorm analysis indicated that expression stability varied between the reference genes in the different experimental conditions, but the two most stable reference genes were sufficient for normalization in most conditions.<em> EsEFem> and <em>Esα-TUB> were sufficient for various stress conditions, <em>EsEF> and <em>EsACT> were suitable for samples of differing germination stages, and <em>EsGAPDH>and <em>Es>UBQ em>were most stable across multiple adult tissue samples. The <em>Es18Sem> gene was unsuitable as a reference gene in our analysis. In addition, the expression level of the drought-stress related transcription factor <em>EsDREB2em>> em>verified the utility of<em> E. songoricumem> reference genes and indicated that no single gene was adequate for normalization on its own. This is the first systematic report on the selection of reference genes in <em>E. songoricumem>, and these data will facilitate future work on gene expression in this species.

  20. Influência de frações da parede celular de levedura (Saccharomyces cerevisiae sobre os índices séricos de glicose e lipídios, microbiota intestinal e produção de ácidos graxos voláteis (AGV de cadeias curtas de ratos em crescimento Influence of yeast (Saccharomyces cerevisiae cell wall fractions on serum indexes of glucose and lipids, intestinal microbiota and production of short-chain volatile fatty acids (VFA in growing rats

    Directory of Open Access Journals (Sweden)

    Saula Goulart Chaud

    2007-06-01

    Full Text Available Os índices séricos de glicose e lipídios, a microbiota intestinal e a produção de ácidos graxos voláteis de cadeias curtas (AGV foram determinados em ratos Wistar submetidos às dietas: padrão (AIN-P, padrão modificada (AIN-M e às dietas contendo frações de parede celular de levedura: glicana insolúvel (GI, manana (M e glicana mais manana (G+M, como única fonte de fibra alimentar. O fracionamento da parede celular (PC foi realizado por processos físicos e químicos de extração, centrifugação e secagem em "spray dryer". Os índices séricos foram dosados através de "kits" comerciais. A microbiota e a produção de AGV foram determinadas nos conteúdos intestinais, incluindo cólon, ceco e reto. Considerando os níveis de colesterol no tempo (T0 e no tempo 28 (T28, as dietas AIN-P, AIN-M e M apresentaram efeito hipocolesterolêmico, tendo em vista que a composição das dietas eram de natureza hipercolesterolêmica. Em relação à glicose sérica, no tempo (T0 observou-se uma elevação geral da glicemia, sugerindo um efeito hiperglicêmico das dietas estudadas. A dieta G+M foi a que apresentou valores significantemente mais elevados de lipídios séricos no tempo T14, e os níveis mais baixos foram observados na dieta M e na dieta GI no T14 e nas dietas AIN-M e AIN-P. A dieta AIN-P foi a que apresentou valor significantemente mais elevado de triacilgliceróis nos tempos T14 e T28. Os níveis mais baixos nos tempos T14 foram constatados para as dietas G+M e GI e no tempo T28 para as dietas AIN-M e M. De um modo geral, não houve modificações significativas na microbiota intestinal dos animais em nenhuma das dietas. Dentre os AGV, o ácido acético foi o predominante, seguido do propiônico e do butírico, em todas as dietas estudadas.The blood serum indexes of glucose and lipids, the intestinal microbiota and the production of volatile fatty acids (VFA were determined in Wistar rats which were fed a standard (AIN-P diet, a

  1. Isolation of the catalase T structural gene of Saccharomyces cerevisiae by functional complementation.

    OpenAIRE

    Spevak, W; Fessl, F; Rytka, J; Traczyk, A; Skoneczny, M; Ruis, H

    1983-01-01

    The catalase T structural gene of Saccharomyces cerevisiae was cloned by functional complementation of a mutation causing specific lack of the enzyme (cttl). Catalase T-deficient mutants were obtained by UV mutagenesis of an S. cerevisiae strain bearing the cas1 mutation, which causes insensitivity of catalase T to glucose repression. Since the second catalase protein of S. cerevisiae, catalase A, is completely repressed on 10% glucose, catalase T-deficient mutant colonies could be detected u...

  2. Persistence of Arcobacter butzleri CCUG 30484 on plastic, stainless steel and glass surfaces Persistência de Arcobacter butzleri CCUG 30404 em superfícies de plástico, aço inox e vidro

    Directory of Open Access Journals (Sweden)

    Libor Cervenka

    2008-09-01

    Full Text Available The persistence of A. butzleri CCUG 30484 on various surfaces under 32% and 64% relative humidity suspended in physiological saline or nutrient broth to simulate relatively clean or soiled conditions was studied using various isolation techniques. Our study revealed that A. butzleri CCUG 30484 cells were able to survive for a considerable period of time, even after the droplet of suspending medium has been visibly dried. An extended survival on polypropylene coupons at both humidity levels was observed, particularly at soiled conditions.Estudou-se a persistência de Arcobacter butzleri CCUG 30404 em várias superfícies de contato com alimentos a 32% e 64% de umidade relativa, suspenso em salina fisiológica e caldo nutriente para simular condições limpas e sujas. Nosso estudo indicou que A. butzleri CCUG 30404 foi capaz de sobreviver por longo tempo, mesmo após a secagem da gota. Observou-se que a sobrevivência for mais prolongada nos cupons de polipropileno, especialmente em condições sujas.

  3. Characterization of oligosaccharides from an antigenic mannan of Saccharomyces cerevisiae.

    Science.gov (United States)

    Young, M; Davies, M J; Bailey, D; Gradwell, M J; Smestad-Paulsen, B; Wold, J K; Barnes, R M; Hounsell, E F

    1998-08-01

    Mannans of the yeast Saccharomyces cerevisiae have been implicated as containing the allergens to which bakers and brewers are sensitive and also the antigen recognized by patients with Crohn's disease. A fraction of S. cerevisiae mannan, Sc500, having high affinity for antibodies in Crohn's patients has been characterized by NMR spectroscopy followed by fragmentation using alkaline elimination, partial acid hydrolysis and acetolysis. The released oligosaccharides were separated by gel filtration on a Biogel P4 column and analyzed by fluorescence labeling, HPLC and methylation analysis. The relationship between structure and antigen activity was measured by competitive ELISA. The antigenic activity of the original high molecular weight mannan could be ascribed to terminal Manalpha1-->3Manalpha1-->2 sequences which are rarely found in human glycoproteins but were over-represented in Sc500 compared to other yeast mannans.

  4. Saccharomyces cerevisiae: a versatile eukaryotic system in virology

    Directory of Open Access Journals (Sweden)

    Breinig Tanja

    2007-10-01

    Full Text Available Abstract The yeast Saccharomyces cerevisiae is a well-established model system for understanding fundamental cellular processes relevant to higher eukaryotic organisms. Less known is its value for virus research, an area in which Saccharomyces cerevisiae has proven to be very fruitful as well. The present review will discuss the main achievements of yeast-based studies in basic and applied virus research. These include the analysis of the function of individual proteins from important pathogenic viruses, the elucidation of key processes in viral replication through the development of systems that allow the replication of higher eukayotic viruses in yeast, and the use of yeast in antiviral drug development and vaccine production.

  5. Heat shock response improves heterologous protein secretion in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Hou, Jin; Österlund, Tobias; Liu, Zihe

    2013-01-01

    The yeast Saccharomyces cerevisiae is a widely used platform for the production of heterologous proteins of medical or industrial interest. However, heterologous protein productivity is often low due to limitations of the host strain. Heat shock response (HSR) is an inducible, global, cellular...... stress response, which facilitates the cell recovery from many forms of stress, e.g., heat stress. In S. cerevisiae, HSR is regulated mainly by the transcription factor heat shock factor (Hsf1p) and many of its targets are genes coding for molecular chaperones that promote protein folding and prevent...... the accumulation of mis-folded or aggregated proteins. In this work, we over-expressed a mutant HSF1 gene HSF1-R206S which can constitutively activate HSR, so the heat shock response was induced at different levels, and we studied the impact of HSR on heterologous protein secretion. We found that moderate and high...

  6. Purification of fluorescently labeled Saccharomyces cerevisiae Spindle Pole Bodies

    Science.gov (United States)

    Davis, Trisha N.

    2016-01-01

    Centrosomes are components of the mitotic spindle responsible for organizing microtubules and establishing a bipolar spindle for accurate chromosome segregation. In budding yeast, Saccharomyces cerevisiae, the centrosome is called the spindle pole body, a highly organized tri-laminar structure embedded in the nuclear envelope. Here we describe a detailed protocol for the purification of fluorescently labeled spindle pole bodes from S. cerevisiae. Spindle pole bodies are purified from yeast using a TAP-tag purification followed by velocity sedimentation. This highly reproducible TAP-tag purification method improves upon previous techniques and expands the scope of in vitro characterization of yeast spindle pole bodies. The genetic flexibility of this technique allows for the study of spindle pole body mutants as well as the study of spindle pole bodies during different stages of the cell cycle. The ease and reproducibility of the technique makes it possible to study spindle pole bodies using a variety of biochemical, biophysical, and microscopic techniques. PMID:27193850

  7. Investigation of nutrient sensing in the yeast Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Eckert-Boulet, Nadine

    2006-01-01

    Gæren Saccharomyces cerevisiae har udviklet komplekse regulatoriske systemer til at kontrollere ekspression af de proteiner, der importerer næringsstoffer, således at disse kun bliver produceret, når der er brug for dem. Dette er tilfældet for hexose-transportører samt aminosyre-transportører (di......Gæren Saccharomyces cerevisiae har udviklet komplekse regulatoriske systemer til at kontrollere ekspression af de proteiner, der importerer næringsstoffer, således at disse kun bliver produceret, når der er brug for dem. Dette er tilfældet for hexose-transportører samt aminosyre...

  8. Identification of pathways controlling DNA damage induced mutation in Saccharomyces cerevisiae.

    Science.gov (United States)

    Lis, Ewa T; O'Neill, Bryan M; Gil-Lamaignere, Cristina; Chin, Jodie K; Romesberg, Floyd E

    2008-05-01

    Mutation in response to most types of DNA damage is thought to be mediated by the error-prone sub-branch of post-replication repair and the associated translesion synthesis polymerases. To further understand the mutagenic response to DNA damage, we screened a collection of 4848 haploid gene deletion strains of Saccharomyces cerevisiae for decreased damage-induced mutation of the CAN1 gene. Through extensive quantitative validation of the strains identified by the screen, we identified ten genes, which included error-prone post-replication repair genes known to be involved in induced mutation, as well as two additional genes, FYV6 and RNR4. We demonstrate that FYV6 and RNR4 are epistatic with respect to induced mutation, and that they function, at least partially, independently of post-replication repair. This pathway of induced mutation appears to be mediated by an increase in dNTP levels that facilitates lesion bypass by the replicative polymerase Pol delta, and it is as important as error-prone post-replication repair in the case of UV- and MMS-induced mutation, but solely responsible for EMS-induced mutation. We show that Rnr4/Pol delta-induced mutation is efficiently inhibited by hydroxyurea, a small molecule inhibitor of ribonucleotide reductase, suggesting that if similar pathways exist in human cells, intervention in some forms of mutation may be possible.

  9. Utilização de Saccharomyces cerevisiae como probiótico para tilápias-do-nilo durante o período de reversão sexual submetidas a um desafio sanitário Saccharomyces cerevisiae as probiotic for Nile Tilapia during the sexual reversion phase under a sanitary challenge

    Directory of Open Access Journals (Sweden)

    Fábio Meurer

    2006-10-01

    Full Text Available Um experimento foi realizado durante 29 dias com o objetivo de avaliar o uso de Saccharomyces cerevisiae (SC como probiótico em rações para tilápias-do-nilo (Oreochromis niloticus durante o período de reversão sexual, submetidas a um desafio sanitário. Foram utilizadas 300 larvas de dois dias de idade (8,9 ± 1,02 mg e 0,71 ± 0,09 cm, distribuídas em um delineamento completamente casualizado, com dois tratamentos e seis repetições, em 12 aquários de 50 L. O desafio sanitário foi o fornecimento diário de 0,5 mL de esterco suíno in natura para cada aquário. Os tratamentos constituíram-se de uma ração comercial para a fase de reversão sexual, adicionada (TP ou não (TT de 0,1% de S. cerevisiae. As larvas foram alimentadas, à vontade, cinco vezes ao dia e, ao final do experimento, foram contadas, medidas e pesadas. Dois alevinos de cada tratamento foram escolhidos aleatoriamente para retirada dos intestinos e contagem do número de bactérias e coliformes totais. O desempenho e a sobrevivência não foram influenciados pelo tratamento. A SC colonizou o intestino somente dos alevinos do TP. Não foram observadas diferenças significativas quanto ao número de bactérias e coliformes totais por grama de conteúdo intestinal e da água dos aquários. A utilização de Saccharomyces cerevisiae como probiótico em rações promoveu a colonização do intestino de tilápias-do-nilo durante o período de reversão sexual, mas não influenciou o desempenho e a sobrevivência em um sistema de cultivo com desafio sanitário.A 29-d experiment was carried out to evaluate the Saccharomyces cerevisiae (SC as probiotic in diets for Nile tilapia (Oreochromis niloticus during the sexual reversion phase, under a sanitary challenge. Three hundred 2-d larvae averaging 8.9 ± 1.02 mg and 0.71 ± 0.09 cm were allotted to a completely randomized design with two treatments and six replicates in twelve 50 L-aquaria. Sanitary challenge consisted of a

  10. Comparison of heterologous xylose transporters in recombinant Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Hahn-Hägerdal Bärbel

    2010-03-01

    Full Text Available Abstract Background Baker's yeast (Saccharomyces cerevisiae has been engineered for xylose utilization to enable production of fuel ethanol from lignocellulose raw material. One unresolved challenge is that S. cerevisiae lacks a dedicated transport system for pentose sugars, which means that xylose is transported by non-specific Hxt transporters with comparatively low transport rate and affinity for xylose. Results In this study, we compared three heterologous xylose transporters that have recently been shown to improve xylose uptake under different experimental conditions. The transporters Gxf1, Sut1 and At5g59250 from Candida intermedia, Pichia stipitis and Arabidopsis thaliana, respectively, were expressed in isogenic strains of S. cerevisiae and the transport kinetics and utilization of xylose was evaluated. Expression of the Gxf1 and Sut1 transporters led to significantly increased affinity and transport rates of xylose. In batch cultivation at 4 g/L xylose concentration, improved transport kinetics led to a corresponding increase in xylose utilization, whereas no correlation could be demonstrated at xylose concentrations greater than 15 g/L. The relative contribution of native sugar transporters to the overall xylose transport capacity was also estimated during growth on glucose and xylose. Conclusions Kinetic characterization and aerobic batch cultivation of strains expressing the Gxf1, Sut1 and At5g59250 transporters showed a direct relationship between transport kinetics and xylose growth. The Gxf1 transporter had the highest transport capacity and the highest xylose growth rate, followed by the Sut1 transporter. The range in which transport controlled the growth rate was determined to between 0 and 15 g/L xylose. The role of catabolite repression in regulation of native transporters was also confirmed by the observation that xylose transport by native S. cerevisiae transporters increased significantly during cultivation in xylose and

  11. YPA: an integrated repository of promoter features in Saccharomyces cerevisiae

    OpenAIRE

    2010-01-01

    This study presents the Yeast Promoter Atlas (YPA, http://ypa.ee.ncku.edu.tw/ or http://ypa.csbb.ntu.edu.tw/) database, which aims to collect comprehensive promoter features in Saccharomyces cerevisiae. YPA integrates nine kinds of promoter features including promoter sequences, genes’ transcription boundaries—transcription start sites (TSSs), five prime untranslated regions (5′-UTRs) and three prime untranslated regions (3′UTRs), TATA boxes, transcription factor binding sites (TFBSs), nucleo...

  12. Cellular Memory of Acquired Stress Resistance in Saccharomyces cerevisiae

    OpenAIRE

    Guan, Qiaoning; Haroon, Suraiya; Bravo, Diego González; Will, Jessica L.; Gasch, Audrey P.

    2012-01-01

    Cellular memory of past experiences has been observed in several organisms and across a variety of experiences, including bacteria “remembering” prior nutritional status and amoeba “learning” to anticipate future environmental conditions. Here, we show that Saccharomyces cerevisiae maintains a multifaceted memory of prior stress exposure. We previously demonstrated that yeast cells exposed to a mild dose of salt acquire subsequent tolerance to severe doses of H2O2. We set out to characterize ...

  13. Sucrose And Saccharomyces Cerevisiae: A Relationship Most Sweet.

    OpenAIRE

    Marques, Wesley Leoricy; Raghavendran, Vijayendran; Stambuk,Boris Ugarte; Gombert, Andreas Karoly

    2016-01-01

    Sucrose is an abundant, readily available and inexpensive substrate for industrial biotechnology processes and its use is demonstrated with much success in the production of fuel ethanol in Brazil. Saccharomyces cerevisiae, which naturally evolved to efficiently consume sugars such as sucrose, is one of the most important cell factories due to its robustness, stress tolerance, genetic accessibility, simple nutrient requirements and long history as an industrial workhorse. This minireview is f...

  14. Interaction of Saccharomyces cerevisiae with gold: toxicity and accumulation.

    Science.gov (United States)

    Karamushka, V I; Gadd, G M

    1999-12-01

    This paper examines the effects of ionic gold on Saccharomyces cerevisiae, as determined by long-term (growth in gold-containing media) and short-term interactions (H+ efflux activity). An increasing gold concentration inhibited growth and at gold concentration used. Both Ca and Mg enhanced the inhibitory effect of gold on the yeast cells with Ca showing a stronger inhibitory effect than Mg.

  15. The enantioselective b-keto ester reductions by Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    HASSAN TAJIK

    2006-09-01

    Full Text Available The enantioselective yeast reduction of aromatic b-keto esters, by use of potassium dihydrogen phosphate, calcium phosphate (monobasic, magnesium sulfate and ammonium tartrate (diammonium salt (10:1:1:50 in water at pH 7 as a buffer for 72–120 h with 45–90 % conversion to the corresponding aromatic -hydroxy esters was achieved by means of Saccharomyces cerevisiae.

  16. The concentration of ammonia regulates nitrogen metabolism in Saccharomyces cerevisiae.

    OpenAIRE

    ter Schure, E G; Silljé, H H; Verkleij, A J; Boonstra, J; Verrips, C T

    1995-01-01

    Saccharomyces cerevisiae was grown in a continuous culture at a single dilution rate with input ammonia concentrations whose effects ranged from nitrogen limitation to nitrogen excess and glucose limitation. The rate of ammonia assimilation (in millimoles per gram of cells per hour) was approximately constant. Increased extracellular ammonia concentrations are correlated with increased intracellular glutamate and glutamine concentrations, increases in levels of NAD-dependent glutamate dehydro...

  17. Calcium dependence of Eugenol tolerance and toxicity in Saccharomyces cerevisiae

    OpenAIRE

    Stephen K Roberts; Martin McAinsh; Hanna Cantopher; Sean Sandison

    2014-01-01

    Eugenol is a plant-derived phenolic compound which has recognised therapeutical potential as an antifungal agent. However little is known of either its fungicidal activity or the mechanisms employed by fungi to tolerate eugenol toxicity. A better exploitation of eugenol as a therapeutic agent will therefore depend on addressing this knowledge gap. Eugenol initiates increases in cytosolic Ca2+ in Saccharomyces cerevisiae which is partly dependent on the plasma membrane calcium channel, Cch1p. ...

  18. Antiproliferative effects of Matricaria chamomilla on Saccharomyces cerevisiae

    OpenAIRE

    Hosseinpour Maryam; Mobini-Dehkordi Mohsen; Saffar Behnaz; Teimori Hossein

    2013-01-01

    Introduction: The Matricaria chamomilla plant is one of the most important plants used for the therapeutic purposes. More than 120 chemical constituents have been identified in Matricaria chamomile plant including 28 terpenoids and 36 flavonoids. This plant has a variety of therapeutic applications including the treatment of diabetes, eczema, wounds and gastrointestinal diseases. The Saccharomyces cerevisiae yeast is a non-pathogenic organism that is used as a model for pathogenic yeasts in o...

  19. Intracellular ethanol accumulation in Saccharomyces cerevisiae during fermentation.

    OpenAIRE

    D'Amore, T; C.J. Panchal; Stewart, G G

    1988-01-01

    An intracellular accumulation of ethanol in Saccharomyces cerevisiae was observed during the early stages of fermentation (3 h). However, after 12 h of fermentation, the intracellular and extracellular ethanol concentrations were similar. Increasing the osmotic pressure of the medium caused an increase in the ratio of intracellular to extracellular ethanol concentrations at 3 h of fermentation. As in the previous case, the intracellular and extracellular ethanol concentrations were similar af...

  20. Influence of dough freezing on Saccharomyces cerevisiae metabolism

    OpenAIRE

    Pejin Dušanka J.; Došanović Irena S.; Popov Stevan D.; Suturović Zvonimir J.; Ranković Jovana A.; Dodić Siniša N.; Dodić Jelena M.; Vučurović Vesna M.

    2007-01-01

    The need to freeze dough is increasing in bakery production. Frozen dough can be stored for a long time without quality change. The capacity of bakery production can be increased in this way, and in the same time, the night shifts can be decreased. Yeast cells can be damaged by freezing process resulting in poor technological quality of dough after defrostation (longer fermentation of dough). The influence of frozen storage time of dough on survival percentage of Saccharomyces cerevisiae was ...

  1. 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.

  2. Biogeographical characterisation of Saccharomyces cerevisiae wine yeast by molecular methods

    Directory of Open Access Journals (Sweden)

    Rosanna eTofalo

    2013-06-01

    Full Text Available Biogeography is the descriptive and explanatory study of spatial patterns and processes involved in the distribution of biodiversity. Without biogeography, it would be difficult to study the diversity of microorganisms because there would be no way to visualise patterns in variation. Saccharomyces cerevisiae, the wine yeast, is the most important species involved in alcoholic fermentation, and in vineyard ecosystems, it follows the principle of everything is everywhere. Agricultural practices such as farming (organic versus conventional and floor management systems have selected different populations within this species that are phylogenetically distinct. In fact, recent ecological and geographic studies highlighted that unique strains are associated with particular grape varieties in specific geographical locations. These studies also highlighted that significant diversity and regional character, or ‘terroir’, have been introduced into the winemaking process via this association. This diversity of wild strains preserves typicity, the high quality and the unique flavour of wines. Recently, different molecular methods were developed to study population dynamics of S. cerevisiae strains in both vineyards and wineries. In this review, we will provide an update on the current molecular methods used to reveal the geographical distribution of S. cerevisiae wine yeast.

  3. Membrane Trafficking in the Yeast Saccharomyces cerevisiae Model

    Directory of Open Access Journals (Sweden)

    Serge Feyder

    2015-01-01

    Full Text Available The yeast Saccharomyces cerevisiae is one of the best characterized eukaryotic models. The secretory pathway was the first trafficking pathway clearly understood mainly thanks to the work done in the laboratory of Randy Schekman in the 1980s. They have isolated yeast sec mutants unable to secrete an extracellular enzyme and these SEC genes were identified as encoding key effectors of the secretory machinery. For this work, the 2013 Nobel Prize in Physiology and Medicine has been awarded to Randy Schekman; the prize is shared with James Rothman and Thomas Südhof. Here, we present the different trafficking pathways of yeast S. cerevisiae. At the Golgi apparatus newly synthesized proteins are sorted between those transported to the plasma membrane (PM, or the external medium, via the exocytosis or secretory pathway (SEC, and those targeted to the vacuole either through endosomes (vacuolar protein sorting or VPS pathway or directly (alkaline phosphatase or ALP pathway. Plasma membrane proteins can be internalized by endocytosis (END and transported to endosomes where they are sorted between those targeted for vacuolar degradation and those redirected to the Golgi (recycling or RCY pathway. Studies in yeast S. cerevisiae allowed the identification of most of the known effectors, protein complexes, and trafficking pathways in eukaryotic cells, and most of them are conserved among eukaryotes.

  4. Overproduction of fatty acids in engineered Saccharomyces cerevisiae.

    Science.gov (United States)

    Li, Xiaowei; Guo, Daoyi; Cheng, Yongbo; Zhu, Fayin; Deng, Zixin; Liu, Tiangang

    2014-09-01

    The long hydrocarbon fatty acyl chain is energy rich, making it an ideal precursor for liquid transportation fuels and high-value oleo chemicals. As Saccharomyces cerevisiae has many advantages for industrial production compared to Escherichia coli. Here, we attempted to engineer Saccharomyces cerevisiae for overproduction of fatty acids. First, disruption of the beta-oxidation pathway, elimination of the acyl-CoA synthetases, overexpression of different thioesterases and acetyl-CoA carboxylase ACC1, and engineering the supply of precursor acetyl-CoA. The engineered strain XL122 produced more than 120 mg/L of fatty acids. In parallel, we inactivated ADH1, the dominant gene for ethanol production, to redirect the metabolic flux to fatty acids synthesis. The engineered strain DG005 produced about 140 mg/L fatty acids. Additionally, Acetyl-CoA carboxylase was identified as a critical bottleneck of fatty acids synthesis in S. cerevisiae with a cell-free system. However, overexpression of ACC1 has little effect on fatty acids biosynthesis. As it has been reported that phosphorylation of ACC1 may influent its activity, so phosphorylation sites of ACC1 were further identified. Although the regulatory mechanisms remain unclear, our results provide rationale for future studies to target this critical step. All these efforts, particularly the discovery of the limiting step are critical for developing a "cell factory" for the overproduction of fatty acids by using type I fatty acids synthase in yeast or other fungi.

  5. Horizontal and vertical growth of S. cerevisiae metabolic network

    Directory of Open Access Journals (Sweden)

    Tramontano Anna

    2011-10-01

    Full Text Available Abstract Background The growth and development of a biological organism is reflected by its metabolic network, the evolution of which relies on the essential gene duplication mechanism. There are two current views about the evolution of metabolic networks. The retrograde model hypothesizes that a pathway evolves by recruiting novel enzymes in a direction opposite to the metabolic flow. The patchwork model is instead based on the assumption that the evolution is based on the exploitation of broad-specificity enzymes capable of catalysing a variety of metabolic reactions. Results We analysed a well-studied unicellular eukaryotic organism, S. cerevisiae, and studied the effect of the removal of paralogous gene products on its metabolic network. Our results, obtained using different paralog and network definitions, show that, after an initial period when gene duplication was indeed instrumental in expanding the metabolic space, the latter reached an equilibrium and subsequent gene duplications were used as a source of more specialized enzymes rather than as a source of novel reactions. We also show that the switch between the two evolutionary strategies in S. cerevisiae can be dated to about 350 million years ago. Conclusions Our data, obtained through a novel analysis methodology, strongly supports the hypothesis that the patchwork model better explains the more recent evolution of the S. cerevisiae metabolic network. Interestingly, the effects of a patchwork strategy acting before the Euascomycete-Hemiascomycete divergence are still detectable today.

  6. Horizontal and vertical growth of S. cerevisiae metabolic network.

    KAUST Repository

    Grassi, Luigi

    2011-10-14

    BACKGROUND: The growth and development of a biological organism is reflected by its metabolic network, the evolution of which relies on the essential gene duplication mechanism. There are two current views about the evolution of metabolic networks. The retrograde model hypothesizes that a pathway evolves by recruiting novel enzymes in a direction opposite to the metabolic flow. The patchwork model is instead based on the assumption that the evolution is based on the exploitation of broad-specificity enzymes capable of catalysing a variety of metabolic reactions. RESULTS: We analysed a well-studied unicellular eukaryotic organism, S. cerevisiae, and studied the effect of the removal of paralogous gene products on its metabolic network. Our results, obtained using different paralog and network definitions, show that, after an initial period when gene duplication was indeed instrumental in expanding the metabolic space, the latter reached an equilibrium and subsequent gene duplications were used as a source of more specialized enzymes rather than as a source of novel reactions. We also show that the switch between the two evolutionary strategies in S. cerevisiae can be dated to about 350 million years ago. CONCLUSIONS: Our data, obtained through a novel analysis methodology, strongly supports the hypothesis that the patchwork model better explains the more recent evolution of the S. cerevisiae metabolic network. Interestingly, the effects of a patchwork strategy acting before the Euascomycete-Hemiascomycete divergence are still detectable today.

  7. Role of social wasps in Saccharomyces cerevisiae ecology and evolution.

    Science.gov (United States)

    Stefanini, Irene; Dapporto, Leonardo; Legras, Jean-Luc; Calabretta, Antonio; Di Paola, Monica; De Filippo, Carlotta; Viola, Roberto; Capretti, Paolo; Polsinelli, Mario; Turillazzi, Stefano; Cavalieri, Duccio

    2012-08-14

    Saccharomyces cerevisiae is one of the most important model organisms and has been a valuable asset to human civilization. However, despite its extensive use in the last 9,000 y, the existence of a seasonal cycle outside human-made environments has not yet been described. We demonstrate the role of social wasps as vector and natural reservoir of S. cerevisiae during all seasons. We provide experimental evidence that queens of social wasps overwintering as adults (Vespa crabro and Polistes spp.) can harbor yeast cells from autumn to spring and transmit them to their progeny. This result is mirrored by field surveys of the genetic variability of natural strains of yeast. Microsatellites and sequences of a selected set of loci able to recapitulate the yeast strain's evolutionary history were used to compare 17 environmental wasp isolates with a collection of strains from grapes from the same region and more than 230 strains representing worldwide yeast variation. The wasp isolates fall into subclusters representing the overall ecological and industrial yeast diversity of their geographic origin. Our findings indicate that wasps are a key environmental niche for the evolution of natural S. cerevisiae populations, the dispersion of yeast cells in the environment, and the maintenance of their diversity. The close relatedness of several wasp isolates with grape and wine isolates reflects the crucial role of human activities on yeast population structure, through clonal expansion and selection of specific strains during the biotransformation of fermented foods, followed by dispersal mediated by insects and other animals.

  8. Early manifestations of replicative aging in the yeast Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    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.

  9. Combinatorial metabolic engineering of Saccharomyces cerevisiae for terminal alkene production.

    Science.gov (United States)

    Chen, Binbin; Lee, Dong-Yup; Chang, Matthew Wook

    2015-09-01

    Biological production of terminal alkenes has garnered a significant interest due to their industrial applications such as lubricants, detergents and fuels. Here, we engineered the yeast Saccharomyces cerevisiae to produce terminal alkenes via a one-step fatty acid decarboxylation pathway and improved the alkene production using combinatorial engineering strategies. In brief, we first characterized eight fatty acid decarboxylases to enable and enhance alkene production. We then increased the production titer 7-fold by improving the availability of the precursor fatty acids. We additionally increased the titer about 5-fold through genetic cofactor engineering and gene expression tuning in rich medium. Lastly, we further improved the titer 1.8-fold to 3.7 mg/L by optimizing the culturing conditions in bioreactors. This study represents the first report of terminal alkene biosynthesis in S. cerevisiae, and the abovementioned combinatorial engineering approaches collectively increased the titer 67.4-fold. We envision that these approaches could provide insights into devising engineering strategies to improve the production of fatty acid-derived biochemicals in S. cerevisiae.

  10. The postmitotic Saccharomyces cerevisiae after spaceflight showed higher viability

    Science.gov (United States)

    Yi, Zong-Chun; Li, Xiao-Fei; Wang, Yan; Wang, Jie; Sun, Yan; Zhuang, Feng-Yuan

    2011-06-01

    The budding yeast Saccharomyces cerevisiae has been proposed as an ideal model organism for clarifying the biological effects caused by spaceflight conditions. The postmitotic S. cerevisiae cells onboard Practice eight recoverable satellite were subjected to spaceflight for 15 days. After recovery, the viability, the glycogen content, the activities of carbohydrate metabolism enzymes, the DNA content and the lipid peroxidation level in yeast cells were analyzed. The viability of the postmitotic yeast cells after spaceflight showed a three-fold increase as compared with that of the ground control cells. Compared to the ground control cells, the lipid peroxidation level in the spaceflight yeast cells markedly decreased. The spaceflight yeast cells also showed an increase in G2/M cell population and a decrease in Sub-G1 cell population. The glycogen content and the activities of hexokinase and succinate dehydrogenase significantly decreased in the yeast cells after spaceflight. In contrast, the activity of malate dehydrogenase showed an obvious increase after spaceflight. These results suggested that microgravity or spaceflight could promote the survival of postmitotic S. cerevisiae cells through regulating carbohydrate metabolism, ROS level and cell cycle progression.

  11. Membrane trafficking in the yeast Saccharomyces cerevisiae model.

    Science.gov (United States)

    Feyder, Serge; De Craene, Johan-Owen; Bär, Séverine; Bertazzi, Dimitri L; Friant, Sylvie

    2015-01-09

    The yeast Saccharomyces cerevisiae is one of the best characterized eukaryotic models. The secretory pathway was the first trafficking pathway clearly understood mainly thanks to the work done in the laboratory of Randy Schekman in the 1980s. They have isolated yeast sec mutants unable to secrete an extracellular enzyme and these SEC genes were identified as encoding key effectors of the secretory machinery. For this work, the 2013 Nobel Prize in Physiology and Medicine has been awarded to Randy Schekman; the prize is shared with James Rothman and Thomas Südhof. Here, we present the different trafficking pathways of yeast S. cerevisiae. At the Golgi apparatus newly synthesized proteins are sorted between those transported to the plasma membrane (PM), or the external medium, via the exocytosis or secretory pathway (SEC), and those targeted to the vacuole either through endosomes (vacuolar protein sorting or VPS pathway) or directly (alkaline phosphatase or ALP pathway). Plasma membrane proteins can be internalized by endocytosis (END) and transported to endosomes where they are sorted between those targeted for vacuolar degradation and those redirected to the Golgi (recycling or RCY pathway). Studies in yeast S. cerevisiae allowed the identification of most of the known effectors, protein complexes, and trafficking pathways in eukaryotic cells, and most of them are conserved among eukaryotes.

  12. Osmo-, thermo- and ethanol- tolerances of Saccharomyces cerevisiae S1

    Directory of Open Access Journals (Sweden)

    Sandrasegarampillai Balakumar

    2012-03-01

    Full Text Available Saccharomyces cerevisiae S1, which is a locally isolated and improved strain showed viability at 40, 45 and 50ºC and produced ethanol at 40, 43 and 45ºC. When the cells were given heat shock at 45ºC for 30min and grown at 40ºC, 100% viability was observed for 60h, and addition of 200gl-1 ethanol has led to complete cell death at 30h. Heat shock given at 45ºC (for 30min has improved the tolerance to temperature induced ethanol shock leading to 37% viability at 30h. when the cells were subjected to ethanol (200gl-1 for 30 min and osmotic shock (sorbitol 300gl-1, trehalose contents in the cells were increased. The heat shocked cells showed better viability in presence of added ethanol. Soy flour supplementation has improved the viability of S. cerevisiae S1 to 80% in presence of 100gl-1 added ethanol and to 60% in presence of 300gl-1 sorbitol. In presence of sorbitol (200gl-1 and ethanol (50gl-1 at 40ºC, 46% viability was retained by S. cerevisiae S1 at 48h and it was improved to 80% by soy flour supplementation.

  13. Antiproliferative effects of Matricaria chamomilla on Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Hosseinpour Maryam

    2013-04-01

    Full Text Available Introduction: The Matricaria chamomilla plant is one of the most important plants used for the therapeutic purposes. More than 120 chemical constituents have been identified in Matricaria chamomile plant including 28 terpenoids and 36 flavonoids. This plant has a variety of therapeutic applications including the treatment of diabetes, eczema, wounds and gastrointestinal diseases. The Saccharomyces cerevisiae yeast is a non-pathogenic organism that is used as a model for pathogenic yeasts in order to identify compounds with antifungal properties and also to identify functional mechanism of these compounds. The aim of this study is to investigate the antifungal effect of Matricaria chamomilla hydroalcoholic extract on S. cerevisiae yeast. Methods: In this study Matricaria chamomilla extract was prepared by maceration method. In order to study the extract effect on growth and survival rate of the yeast cell, the spectrophotometry and methylene blue staining methods were used. Excel and SPSS 11 softwares were used to determine amounts and to infer the difference between control and treatment samples. Results: Results obtained from spectrophotometry and analyses of methylene blue staining showed that the Matricaria chamomilla extract at the concentration of 3000 μg/ml caused a significant decrease in the yeast growth and reduced the cells survival rate up to 48% (p< 0.05. Conclusion: Results of this research confirm that the hydroalcoholic extract of Matricaria chamomilla has antiproliferative effect on Saccharomyces cerevisiae.

  14. Saccharomyces cerevisiae in the Production of Whisk(ey

    Directory of Open Access Journals (Sweden)

    Graeme M. Walker

    2016-12-01

    Full Text Available Whisk(ey is a major global distilled spirit beverage. Whiskies are produced from cereal starches that are saccharified, fermented and distilled prior to spirit maturation. The strain of Saccharomyces cerevisiae employed in whisky fermentations is crucially important not only in terms of ethanol yields, but also for production of minor yeast metabolites which collectively contribute to development of spirit flavour and aroma characteristics. Distillers must therefore pay very careful attention to the strain of yeast exploited to ensure consistency of fermentation performance and spirit congener profiles. In the Scotch whisky industry, initiatives to address sustainability issues facing the industry (for example, reduced energy and water usage have resulted in a growing awareness regarding criteria for selecting new distilling yeasts with improved efficiency. For example, there is now a desire for Scotch whisky distilling yeasts to perform under more challenging conditions such as high gravity wort fermentations. This article highlights the important roles of S. cerevisiae strains in whisky production (with particular emphasis on Scotch and describes key fermentation performance attributes sought in distiller’s yeast, such as high alcohol yields, stress tolerance and desirable congener profiles. We hope that the information herein will be useful for whisky producers and yeast suppliers in selecting new distilling strains of S. cerevisiae, and for the scientific community to stimulate further research in this area.

  15. Ciclohexadespipeptide beauvericin degradation by different strains of Saccharomyces cerevisiae.

    Science.gov (United States)

    Meca, G; Zhou, T; Li, X Z; Ritieni, A; Mañes, J

    2013-09-01

    The interaction between the mycotoxin beauvericin (BEA) and 9 yeast strains of Saccharomyces cerevisiae named LO9, YE-2, YE5, YE-6, YE-4, A34, A17, A42 and A08 was studied. The biological degradations were carried out under aerobic conditions in the liquid medium of Potato Dextrose Broth (PDB) at 25°C for 48 h and in a food/feed system composed of corn flour at 37°C for 3 days, respectively. BEA present in fermented medium and corn flour was determined using liquid chromatography coupled to the mass spectrometry detector in tandem (LC-MS/MS) and the BEA degradation products produced during the fermentations were determined using the technique of the liquid chromatography coupled to a linear ion trap (LIT). Results showed that the S. cerevisiae strains reduced meanly the concentration of the BEA present in PDB by 86.2% and in a food system by 71.1%. All the S. cerevisiae strains used in this study showed a significant BEA reduction during the fermentation process employed.

  16. <em>Saccharomyces cerevisiae> CCMI 885 secretes peptides that inhibit the growth of some non-<em>Saccharomyces em>wine-related strains

    DEFF Research Database (Denmark)

    Albergaria, Helena; Francisco, Diana; Gori, Klaus;

    2010-01-01

    of those supernatants seemed to contain antimicrobial peptides active against H. guilliermondii. Thus, the (2-10) kDa protein fraction was concentrated and its inhibitory effect tested against strains of Kluyveromyces marxianus, Kluyveromyces thermotolerans, Torulaspora delbrueckii and H. guilliermondii...

  17. Synthesis, Crystal Structure and Luminescent Property of Cd (II Complex with <em>N-Benzenesulphonyl-L>-leucine

    Directory of Open Access Journals (Sweden)

    Xishi Tai

    2012-09-01

    Full Text Available A new trinuclear Cd (II complex [Cd3(L6(2,2-bipyridine3] [L =<em> Nem>-phenylsulfonyl-L>-leucinato] has been synthesized and characterized by elemental analysis, IR and X-ray single crystal diffraction analysis. The results show that the complex belongs to the orthorhombic, space group<em> Pem>212121 with<em> aem> = 16.877(3 Å, <em>b> em>= 22.875(5 Å, <em>c em>= 29.495(6 Å, <em>α> em>= <emem>= <emem>= 90°, <em>V> em>= 11387(4 Å3, <em>Z> em>= 4, <em>Dc>= 1.416 μg·m−3, <emem>= 0.737 mm−1, <em>F> em>(000 = 4992, and final <em>R>1 = 0.0390, <em>ωR>2 = 0.0989. The complex comprises two seven-coordinated Cd (II atoms, with a N2O5 distorted pengonal bipyramidal coordination environment and a six-coordinated Cd (II atom, with a N2O4 distorted octahedral coordination environment. The molecules form one dimensional chain structure by the interaction of bridged carboxylato groups, hydrogen bonds and p-p interaction of 2,2-bipyridine. The luminescent properties of the Cd (II complex and <em>N-Benzenesulphonyl-L>-leucine in solid and in CH3OH solution also have been investigated.

  18. PRODUCTION, PROPERTIES AND APPLICATION OF SACCHAROMYCES CEREVISIAE VGSH-2 INULINASE

    Directory of Open Access Journals (Sweden)

    G. P. Shuvaeva

    2014-01-01

    Full Text Available Summary. Experimental data on an acid and thermal inactivation of a high refined inulinase (2,1-β-D- fructanfructanohydrolase, KF 3.2.17, produced by the race of Saccharomyces cerevisiae VGSh-2 yeast are presented. The strain of S. cerevisiae VGSh-2 was produced by the method of the induced mutagenesis and deposited to the collection of pure cultures of the chair of biochemistry and biotechnology of Voronezh state university of engineering technologies. The cells of source culture (S. cerevisiae XII were affected step-by-step by the ultra-violet radiation (UFR and UFR in a complex with a chemical mutagen (etilenimine. The culture was grown up by the method of liquid-phase deep cultivation on a constant nutrient medium. Refining conditions for inulinase are sorted out. Activity of enzyme dependence on physical and chemical factors (рН and temperature is obtained and numerical values of the main kinetic constants – Km and Vmax are determined. The structure of enzyme molecule is studied by an infrared-spectroscopy method: the type and relative quantity of elements of secondary structure of protein are defined. Substrate binding groups of the active center of an inulinase are found. The comparative analysis of the ability to hydrolysis of inulin in several enzyme preparations from Jerusalem artichoke and to the subsequent their fermentation by the VGSh-2 and XI S. cerevisiae yeasts is carried out. Optimum conditions of enzyme hydrolysis of inulin are selected. Research of the fermentation process of starchcontaining raw materials by yeasts of VGSh-2 and XI races is done. It is established that the using of VGSh-2 S. cerevisiae yeast for a grain wort and the Jerusalem artichoke fermentation, allows to increase an extraction of ethyl alcohol comparing to control race, to improve its quality characteristics, and also allows to predict the using of new race in the food industry for production ethanol from grain raw materials and a fermentation of

  19. Switching the mode of sucrose utilization by Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Miletti Luiz C

    2008-02-01

    Full Text Available 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 sucrose consumption rates are controlled by the external addition of sugar aiming at its low concentrations in the fermentor, is the classical bioprocessing alternative to prevent sugar fermentation by yeasts. However, fed-batch fermentations present drawbacks that could be overcome by simpler batch cultures at relatively high (e.g. 20 g/L initial sugar concentrations. In this study, a S. cerevisiae strain lacking invertase activity was engineered to transport sucrose into the cells through a low-affinity and low-capacity sucrose-H+ symport activity, and the growth kinetics and biomass yields on sucrose analyzed using simple batch cultures. Results We have deleted from the genome of a S. cerevisiae strain lacking invertase the high-affinity sucrose-H+ symporter encoded by the AGT1 gene. This strain could still grow efficiently on sucrose due to a low-affinity and low-capacity sucrose-H+ symport activity mediated by the MALx1 maltose permeases, and its further intracellular hydrolysis by cytoplasmic maltases. Although sucrose consumption by this engineered yeast strain was slower than with the parental yeast strain, the cells grew efficiently on sucrose due to an increased respiration of the carbon source. Consequently, this engineered yeast strain produced less ethanol and 1.5 to 2 times more biomass when cultivated in simple batch mode using 20 g/L sucrose as the carbon source. Conclusion Higher cell densities during batch cultures on 20 g/L sucrose were achieved by using a S. cerevisiae strain engineered in the sucrose uptake system. Such result was accomplished by

  20. Redox balancing in recombinant strains of Saccharomyces cerevisiae

    Energy Technology Data Exchange (ETDEWEB)

    Anderlund, M.

    1998-09-01

    In metabolically engineered Saccharomyces cerevisiae expressing Pichia stipitis XYL1 and XYL2 genes, encoding xylose reductase (XR) and xylitol dehydrogenase (XDH), respectively, xylitol is excreted as the major product during anaerobic xylose fermentation and only low yields of ethanol are produced. This has been interpreted as a result of the dual cofactor dependence of XR and the exclusive use of NAD{sup +} by XDH. The excretion of xylitol was completely stopped and the formation of glycerol and acetic acid were reduced in xylose utilising S. cerevisiae strains cultivated in oxygen-limited conditions by expressing lower levels of XR than of XDH. The expression level of XYL1 and XYL2 were controlled by changing the promoters and transcription directions of the genes. A new functional metabolic pathway was established when Thermus thermophilus xylA gene was expressed in S. cerevisiae. The recombinant strain was able to ferment xylose to ethanol when cultivated on a minimal medium containing xylose as only carbon source. In order to create a channeled metabolic transfer in the two first steps of the xylose metabolism, XYL1 and XYL2 were fused in-frame and expressed in S. cerevisiae. When the fusion protein, containing a linker of three amino acids, was co expressed together with native XR and XDH monomers, enzyme complexes consisting of chimeric and native subunits were formed. The total activity of these complexes exhibited 10 and 9 times higher XR and XDH activity, respectively, than the original conjugates, consisting of only chimeric subunits. This strain produced less xylitol and the xylitol yield was lower than with strains only expressing native XR and XDH monomers. In addition, more ethanol and less acetic acid were formed. A new gene encoding the cytoplasmic transhydrogenase from Azotobacter vinelandii was cloned. The enzyme showed high similarity to the family of pyridine nucleotide-disulphide oxidoreductase. To analyse the physiological effect of

  1. [Saccharomyces cerevisiae fungemia in an elderly patient following probiotic treatment].

    Science.gov (United States)

    Eren, Zehra; Gurol, Yeşim; Sonmezoglu, Meral; Eren, Hatice Seyma; Celik, Gülden; Kantarci, Gülçin

    2014-04-01

    Saccharomyces cerevisiae, known as baker's yeast, is also used as a probiotic agent to treat gastroenteritis by modulating the endogenous flora and immune system. However, since there have been increasing reports of fungemia due to S.cerevisiae and its subspecies S.boulardii, it is recommended that probiotics should be cautiously used in immunosuppressed patients, people with underlying diseases and low-birth weight babies. To emphasize this phenomenon, in this report, a case of S.cerevisiae fungemia developed in a patient given probiotic treatment for antibiotic-associated diarrhea, was presented. An 88-year-old female patient was admitted to our hospital with left hip pain, hypotension, and confusion. Her medical history included hypertension, chronic renal failure, left knee replacement surgery, and recurrent urinary tract infections due to neurogenic bladder. She was transferred to the intensive care unit with the diagnosis of urosepsis. After obtaining blood and urine samples for culture, empirical meropenem (2 x 500 mg) and linezolid (1 x 600 mg) treatment were administered. A central venous catheter (CVC) was inserted and after one day of inotropic support, her hemodynamic parameters were stabilized. The urine culture obtained on admission yielded extended-spectrum beta-lactamase-producing Klebsiella pneumoniae and Escherichia coli. Urine culture was repeated after three days and no bacteria were isolated. On the 4th day of admission she developed diarrhea. Toxin A/B tests for Clostridium difficile were negative. To relieve diarrhea, S.boulardii (Reflor 250 mg capsules, Sanofi Aventis, Turkey) was administered twice a day, without opening capsules. Two days later, her C-reactive protein (CRP) level increased from 23.2 mg/L to 100 mg/L without fever. Her blood culture taken from the CVC yielded S.cerevisiae. Linezolid and meropenem therapies were stopped on the 13th and 14th days, respectively, while prophylactic fluconazole therapy was replaced with

  2. Transcriptome-Based Characterization of Interactions between Saccharomyces cerevisiae and Lactobacillus delbrueckii subsp. bulgaricus in Lactose-Grown Chemostat Cocultures

    NARCIS (Netherlands)

    Mendes, F.; Sieuwerts, S.; De Hulster, E.; Almering, M.J.; Luttik, M.A.; Pronk, J.T.; Smid, E.J.; Bron, P.A.; Daran-Lapujade, P.

    2013-01-01

    Mixed populations of Saccharomyces cerevisiae yeasts and lactic acid bacteria occur in many dairy, food, and beverage fermentations, but knowledge about their interactions is incomplete. In the present study, interactions between Saccharomyces cerevisiae and Lactobacillus delbrueckii subsp. bulgaric

  3. Transcriptome-based characterization of interactions between Saccharomyces cerevisiae and Lactobacillus delbrueckii subsp. bulgaricus in lactose-grown chemostat cocultures

    NARCIS (Netherlands)

    Mendes, F.; Sieuwerts, S.; Hulster, de E.; Almering, M.J.; Luttik, M.A.H.; Pronk, J.T.; Smid, E.J.; Baron, P.A.; Daran-Lapujade, P.

    2013-01-01

    Mixed populations of Saccharomyces cerevisiae yeasts and lactic acid bacteria occur in many dairy, food, and beverage fermentations, but knowledge about their interactions is incomplete. In the present study, interactions between Saccharomyces cerevisiae and Lactobacillus delbrueckii subsp. bulgaric

  4. Formigas como veiculadoras de microrganismos em ambiente hospitalar Ants as carriers of microorganisms in hospital environments

    Directory of Open Access Journals (Sweden)

    Rogério dos Santos Pereira

    2008-10-01

    Full Text Available Existe preocupação sobre as reais possibilidades de agravos à saúde pública que possam ser causados pela veiculação de agentes patogênicos através de formigas urbanas. O presente trabalho teve por objetivo isolar e identificar os microrganismos associados às formigas em ambiente hospitalar. Foram coletadas 125 formigas, da mesma espécie, em diferentes unidades de um Hospital Universitário. Cada formiga foi coletada com swab embebido em solução fisiológica e transferida para um tubo com caldo Brain Heart Infusion e incubados 35ºC por 24 horas. A partir de cada tubo, com crescimento, foram realizadas inoculações, em meios específicos, para isolamento dos microrganismos. As formigas apresentaram alta capacidade de veiculação de grupos de microrganismos, sendo que 63,5% das cepas eram bacilos Gram positivos produtores de esporos, 6,3% eram bacilos Gram negativos, cocos Gram positivos corresponderam a 23,1% das cepas, 6,7% eram fungos filamentosos e 0,5% eram leveduras. Desta forma, pode-se inferir que as formigas podem ser um dos responsáveis pela disseminação de microrganismos em ambientes hospitalares.Concern exists regarding the real possibility of public health threats caused by pathogenic agents that are carried by urban ants. The present study had the objective of isolating and identifying the microorganisms that are associated with ants in hospital environments. One hundred and twenty-five ants of the same species were collected from different units of a university hospital. Each ant was collected using a swab soaked with physiological solution and was transferred to a tube containing brain heart infusion broth and incubated at 35ºC for 24 hours. From each tube, with growth, inoculations were made into specific culturing media, to isolate any microorganisms. The ants presented a high capacity for carrying microorganism groups: spore-producing Gram-positive bacilli 63.5%, Gram-negative bacilli 6.3%, Gram-positive cocci

  5. Metais pesados em LATOSSOLO tratado com lodo de esgoto e em plantas de cana-de-açúcar Heavy metals in an Oxisol treated with sewage sludge and in sugarcane plants

    Directory of Open Access Journals (Sweden)

    Fernando Carvalho Oliveira

    2001-09-01

    Full Text Available A presença de metais pesados no lodo de esgoto constitui um dos maiores entraves para sua aplicação em solos agrícolas. Neste contexto, o presente trabalho teve como objetivos avaliar os efeitos de aplicações sucessivas de lodo de esgoto sobre o acúmulo de metais pesados num LATOSSOLO AMARELO Distrófico e em plantas de cana-de-açúcar e a fitodisponibilidade desses elementos através de extratores químicos. O experimento foi conduzido nos anos agrícolas 1996/97 e 1997/98 sendo que, no primeiro ano, além dos tratamentos calagem + adubação mineral e testemunha, foram aplicadas em área total, doses equivalentes a 33, 66 e 99 mg ha-1 (base seca de lodo de esgoto. Em 1997/98 o lodo foi reaplicado em doses equivalentes a 37, 74 e 110 mg ha-1 (base seca. Foram detectados acúmulos de Cu, Cr, Ni e Zn na camada 0 0,2 m do solo. As concentrações de Cd, Cr, Ni e Pb nas amostras de plantas de cana-de-açúcar estiveram abaixo dos limites de determinação do método analítico empregado, porém, no caldo, a presença de Cd, Cr e Ni, esteve abaixo de 0,02 mg kg-1. Os teores de Cu e Zn nas várias partes da cana-de-açúcar não foram superiores aos limites normais de variação encontrados na literatura. As soluções extratoras apresentaram eficiência apenas na avaliação da fitodisponibilidade do Zn, determinado nas amostras de colmo e caldo, no ano agrícola 1997/98.The concern about the presence of heavy metals in plants growing in soils treated with sewage sludge can be a restricting factor for the use of this waste in agriculture. The aim of this paper was to evaluate the possibility of heavy metal accumulation in an acid soil after two successive sewage sludge applications and the availability, using chemical extractants for a typic hapludox, of these metals to sugarcane plants. The experiment was managed during two years, 1996/1997 and 1997/1998, and had 5 treatments in a randomized block design: lime + mineral fertilization

  6. Prevention of post weaning diarrhoea by a <em>Saccharomyces cerevisiae>-derived product based on whole yeast

    DEFF Research Database (Denmark)

    Jensen, K. H.; Damgaard, B. M.; Andresen, Lars Ole;

    2013-01-01

    from each litter. In individually housed piglets the faecal consistency score (FCS) was affected by an interaction between days PW, treatment group, and challenge group (P=0.005). In general, FCS was lower in placebo than in E. coli-challenged piglets and in PSP and PP piglets than in C piglets....... The PSP and PP piglets had lower risk of PWD, defined as FCS > 3, on d 2 to 6 PW compared to C piglets (P=0.014 and P=0.001, respectively). This effect was evident in both placebo and E. coli-challenged PP piglets (P=0.010 and P=0.038, respectively), whereas PSP piglets only differed from C in E. coli...

  7. Ensaio de adubação N-P-K em cana-de-açúcar A N-P-K fertilizer experiment for the sugar cane

    Directory of Open Access Journals (Sweden)

    R. Alvarez

    1960-01-01

    Full Text Available No presente trabalho são apresentados os resultados obtidos em um ensaio de adubação de cana-de-açúcar, instalado em terra roxa-misturada do Glacial, na Usina Esmeralda, Município de Santo Antônio da Posse, e conduzido de março de 1957 a agosto de 1958. O delineamento experimental, com cinco repetições, foi o de blocos ao acaso, constando de oito tratamentos: N0P0K0, N0P2K2, N1P2K2, N2P0K2, N2P1K2, N2P2K1 N2P2K0 e N2P2K2, em que o nitrogênio, fósforo e potássio foram estudados nos níveis de 0,80 e 160 kg/ha. Os resultados obtidos permitiram as seguintes observações: a o fósforo e o nitrogênio proporcionaram aumentos apreciáveis na produção de cana e influíram favoravelmente na riqueza do caldo de cana-de-açucar; b os aumentos de produção e riqueza do caldo, devidos ao potássio não alcançaram significação no nível de 5%.The sugar cane yield response to various combinations of three levels of N-P-K was studied in an experiment carried out on a Glacial type of mixed red soil ("terra-roxa-misturada", at the Usina Esmeralda, from March 1957 to August 1958. The three levels, 0, 80 and 160 kg/ha of N-P-K were combined as follows: N0P0K0, N0P2K2,N1P2K2, N2P0K2, N2P1K2, N2P2K1, N2P2K0, and N2P2K2. Five replications of the treatments were laid out in ramdomized plots. The results obtained permitted the following conclusions: (a Phosphorus and nitrogen increased the yeld appreciably and improved the sugar content of the canes; (b the increase in yield and in sugar content due to potassium was not significant at the 5% level.

  8. 40 CFR 180.1246 - Yeast Extract Hydrolysate from Saccharomyces cerevisiae: exemption from the requirement of a...

    Science.gov (United States)

    2010-07-01

    ... Saccharomyces cerevisiae: exemption from the requirement of a tolerance. 180.1246 Section 180.1246 Protection of... Saccharomyces cerevisiae: exemption from the requirement of a tolerance. This regulation establishes an... Hydrolysate from Saccharomyces cerevisiae on all food commodities when applied/used for the management...

  9. Invertase SUC2 Is the Key Hydrolase for Inulin Degradation in Saccharomyces cerevisiae

    OpenAIRE

    Wang, Shi-An; Li, Fu-li

    2013-01-01

    Specific Saccharomyces cerevisiae strains were recently found to be capable of efficiently utilizing inulin, but genetic mechanisms of inulin hydrolysis in yeast remain unknown. Here we report functional characteristics of invertase SUC2 from strain JZ1C and demonstrate that SUC2 is the key enzyme responsible for inulin metabolism in S. cerevisiae.

  10. Physiological impact and context dependency of transcriptional responses: a chemostat study in Saccharomyces cerevisiae

    NARCIS (Netherlands)

    Tai, S.L.

    2007-01-01

    This thesis is a compilation of a four-year PhD project on bakers' yeast (Saccharomyces cerevisiae). Since the entire S. cerevisiae genome sequence became available in 1996, DNA-microarray analysis has become a popular high-information-density tool for analyzing gene expression in this important ind

  11. Biopharmaceutical protein production bySaccharomyces cerevisiae: current state and future prospects

    DEFF Research Database (Denmark)

    Huang, Mingtao; Bao, Jichen; Nielsen, Jens

    2014-01-01

    tasks with low cost, high productivity and proper post-translational modifications. The yeast Saccharomyces cerevisiae is one of these preferred cell factories as it meets many of the requirements. There are several reports on improvement of recombinant protein production by S. cerevisiae through...

  12. ISOLATION OF A CYTOCHROME P-450 STRUCTURAL GENE FROM SACCHAROMYCES CEREVISIAE

    Science.gov (United States)

    We have transformed a Saccharomyces cerevisiae host with an S. cerevisiae genomic library contained in the shuttle vector YEp24 and screened the resultant transformants for resistance to ketoconazole (Kc), an inhibitor of the cytochrome P-450 (P-450) enzyme lanosterol 14-demethyl...

  13. Creation of a synthetic xylose-inducible promoter for Saccharomyces cerevisiae

    Science.gov (United States)

    Saccharomyces cerevisiae is currently used to produce ethanol from glucose, but it cannot utilize five-carbon sugars contained in the hemicellulose component of biomass feedstocks. S. cerevisiae strains engineered for xylose fermentation have been made using constitutive promoters to express the req...

  14. Draft Genome Sequence of the Beer Spoilage Bacterium Megasphaera cerevisiae Strain PAT 1T

    OpenAIRE

    Kutumbaka, Kirthi K.; Pasmowitz, Joshua; Mategko, James; Reyes, Dindo; Friedrich, Alex; Han, Sukkyun; Martens-Habbena, Willm; Neal-McKinney, Jason; Janagama, Harish K.; Nadala, Cesar; Samadpour, Mansour

    2015-01-01

    The genus Megasphaera harbors important spoilage organisms that cause beer spoilage by producing off flavors, undesirable aroma, and turbidity. Megasphaera cerevisiae is mainly found in nonpasteurized low-alcohol beer. In this study, we report the draft genome of the type strain of the genus, M. cerevisiae strain PAT 1T.

  15. [Morphological and biochemical characteristics of new isolates Saccharomyces cerevisiae U-503].

    Science.gov (United States)

    Abramov, Sh A; Kotenko, S Ts; Aliverdieva, D A

    1997-01-01

    Compared with S. cerevisiae N73, its laser irradiation-induced mutant S. cerevisiae U-503 exhibited a significantly higher respiration rate. Electron microscopic changes consistent with this finding were found in the mitochondrial system of mutant cells. The mutant strain retained its physiological and biochemical properties over a nine-year storage period.

  16. <em>α>-Glucosidase Inhibitory Constituents from <em>Acanthopanax senticosusem> Harm Leaves

    Directory of Open Access Journals (Sweden)

    Hai-Xue Kuang

    2012-05-01

    Full Text Available A new triterpene glycoside, 3-<em>O-[(α>-L-rhamnopyranosyl(1→2]-[<em>β>-D-glucuronopyranosyl-6-<em>O>-methyl ester]-olean-12-ene-28-olic acid (1 and a new indole alkaloid, 5-methoxy-2-oxoindolin-3-acetic acid methyl ester (5 were isolated from the leaves of <em>Acanthopanax senticosusem> Harms along with six known compounds. The structures of the new compounds were determined by means of 2D-NMR experiments and chemical methods. All the isolated compounds were evaluated for their glycosidase inhibition activities and compound 6 showed significant <em>α>-glucosidase inhibition activity.

  17. Growth and fermentation characteristics of Saccharomyces cerevisiae NK28 isolated from kiwi fruit.

    Science.gov (United States)

    Lee, Jong-Sub; Park, Eun-Hee; Kim, Jung-Wan; Yeo, Soo-Hwan; Kim, Myoung-Dong

    2013-09-28

    The influences of glucose concentration, initial medium acidity (pH), and temperature on the growth and ethanol production of Saccharomyces cerevisiae NK28, which was isolated from kiwi fruit, were examined in shake flask cultures. The optimal glucose concentration, initial medium pH, and temperature for ethanol production were 200 g/l, pH 6.0, and 35oC, respectively. Under this growth condition, S. cerevisiae NK28 produced 98.9 ± 5.67 g/l ethanol in 24 h with a volumetric ethanol production rate of 4.12 ± 0.24 g/l·h. S. cerevisiae NK28 was more tolerant to heat and ethanol than laboratory strain S. cerevisiae BY4742, and its tolerance to ethanol and fermentation inhibitors was comparable to that of an ethanologen, S. cerevisiae D5A.

  18. Oral administration of myostatin-specific recombinant Saccharomyces cerevisiae vaccine in rabbit.

    Science.gov (United States)

    Liu, Zhongtian; Zhou, Gang; Ren, Chonghua; Xu, Kun; Yan, Qiang; Li, Xinyi; Zhang, Tingting; Zhang, Zhiying

    2016-04-29

    Yeast is considered as a simple and cost-effective host for protein expression, and our previous studies have proved that Saccharomyces cerevisiae can deliver recombinant protein and DNA into mouse dendritic cells and can further induce immune responses as novel vaccines. In order to know whether similar immune responses can be induced in rabbit by oral administration of such recombinant S. cerevisiae vaccine, we orally fed the rabbits with heat-inactivated myostatin-recombinant S. cerevisiae for 5 weeks, and then myostatin-specific antibody in serum was detected successfully by western blotting and ELISA assay. The rabbits treated with myostatin-recombinant S. cerevisiae vaccine grew faster and their muscles were much heavier than that of the control group. As a common experimental animal and a meat livestock with great economic value, rabbit was proved to be the second animal species that have been successfully orally immunized by recombinant S. cerevisiae vaccine after mice.

  19. Clinical Saccharomyces cerevisiae isolates cannot cross the epithelial barrier in vitro.

    Science.gov (United States)

    Pérez-Torrado, Roberto; Llopis, Silvia; Jespersen, Lene; Fernández-Espinar, Teresa; Querol, Amparo

    2012-06-15

    Saccharomyces cerevisiae is generally considered to be a safe organism and is essential to produce many different kinds of foods as well as being widely used as a dietary supplement. However, several isolates, which are genetically related to brewing and baking yeasts, have shown virulent traits, being able to produce human infections in immunodeficient patients. Previously it has been shown that the administration of S. cerevisiae clinical isolates can lead to systemic infections, reaching several organs in murine systems. In this work, we studied S. cerevisiae clinical isolates in an in vitro intestinal epithelial barrier model, comparing their behaviour with that of several strains of the related pathogens Candida glabrata and Candida albicans. The results showed that, in contrast to C. glabrata and C. albicans, S. cerevisiae was not able to cross the intestinal barrier. We concluded that S. cerevisiae can only perform opportunistic or passive crossings when epithelial barrier integrity is previously compromised.

  20. An improved method of xylose utilization by recombinant Saccharomyces cerevisiae.

    Science.gov (United States)

    Ma, Tien-Yang; Lin, Ting-Hsiang; Hsu, Teng-Chieh; Huang, Chiung-Fang; Guo, Gia-Luen; Hwang, Wen-Song

    2012-10-01

    The aim of this study was to develop a method to optimize expression levels of xylose-metabolizing enzymes to improve xylose utilization capacity of Saccharomyces cerevisiae. A xylose-utilizing recombinant S. cerevisiae strain YY2KL, able to express nicotinamide adenine dinucleotide phosphate, reduced (NADPH)-dependent xylose reductase (XR), nicotinamide adenine dinucleotide (NAD(+))-dependent xylitol dehydrogenase (XDH), and xylulokinase (XK), showed a low ethanol yield and sugar consumption rate. To optimize xylose utilization by YY2KL, a recombinant expression plasmid containing the XR gene was transformed and integrated into the aur1 site of YY2KL. Two recombinant expression plasmids containing an nicotinamide adenine dinucleotide phosphate (NADP(+))-dependent XDH mutant and XK genes were dually transformed and integrated into the 5S ribosomal DNA (rDNA) sites of YY2KL. This procedure allowed systematic construction of an S. cerevisiae library with different ratios of genes for xylose-metabolizing enzymes, and well-grown colonies with different xylose fermentation capacities could be further selected in yeast protein extract (YPX) medium (1 % yeast extract, 2 % peptone, and 2 % xylose). We successfully isolated a recombinant strain with a superior xylose fermentation capacity and designated it as strain YY5A. The xylose consumption rate for strain YY5A was estimated to be 2.32 g/gDCW/h (g xylose/g dry cell weight/h), which was 2.34 times higher than that for the parent strain YY2KL (0.99 g/gDCW/h). The ethanol yield was also enhanced 1.83 times by this novel method. Optimal ratio and expression levels of xylose-metabolizing enzymes are important for efficient conversion of xylose to ethanol. This study provides a novel method that allows rapid and effective selection of ratio-optimized xylose-utilizing yeast strains. This method may be applicable to other multienzyme systems in yeast.

  1. High level secretion of cellobiohydrolases by Saccharomyces cerevisiae

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    Ahlgren Simon

    2011-09-01

    Full Text Available Abstract Background The main technological impediment to widespread utilization of lignocellulose for the production of fuels and chemicals is the lack of low-cost technologies to overcome its recalcitrance. Organisms that hydrolyze lignocellulose and produce a valuable product such as ethanol at a high rate and titer could significantly reduce the costs of biomass conversion technologies, and will allow separate conversion steps to be combined in a consolidated bioprocess (CBP. Development of Saccharomyces cerevisiae for CBP requires the high level secretion of cellulases, particularly cellobiohydrolases. Results We expressed various cellobiohydrolases to identify enzymes that were efficiently secreted by S. cerevisiae. For enhanced cellulose hydrolysis, we engineered bimodular derivatives of a well secreted enzyme that naturally lacks the carbohydrate-binding module, and constructed strains expressing combinations of cbh1 and cbh2 genes. Though there was significant variability in the enzyme levels produced, up to approximately 0.3 g/L CBH1 and approximately 1 g/L CBH2 could be produced in high cell density fermentations. Furthermore, we could show activation of the unfolded protein response as a result of cellobiohydrolase production. Finally, we report fermentation of microcrystalline cellulose (Avicel™ to ethanol by CBH-producing S. cerevisiae strains with the addition of beta-glucosidase. Conclusions Gene or protein specific features and compatibility with the host are important for efficient cellobiohydrolase secretion in yeast. The present work demonstrated that production of both CBH1 and CBH2 could be improved to levels where the barrier to CBH sufficiency in the hydrolysis of cellulose was overcome.

  2. Can yeast (S. cerevisiae metabolic volatiles provide polymorphic signaling?

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    J Roman Arguello

    Full Text Available Chemical signaling between organisms is a ubiquitous and evolutionarily dynamic process that helps to ensure mate recognition, location of nutrients, avoidance of toxins, and social cooperation. Evolutionary changes in chemical communication systems progress through natural variation within the organism generating the signal as well as the responding individuals. A promising yet poorly understood system with which to probe the importance of this variation exists between D. melanogaster and S. cerevisiae. D. melanogaster relies on yeast for nutrients, while also serving as a vector for yeast cell dispersal. Both are outstanding genetic and genomic models, with Drosophila also serving as a preeminent model for sensory neurobiology. To help develop these two genetic models as an ecological model, we have tested if - and to what extent - S. cerevisiae is capable of producing polymorphic signaling through variation in metabolic volatiles. We have carried out a chemical phenotyping experiment for 14 diverse accessions within a common garden random block design. Leveraging genomic sequences for 11 of the accessions, we ensured a genetically broad sample and tested for phylogenetic signal arising from phenotypic dataset. Our results demonstrate that significant quantitative differences for volatile blends do exist among S. cerevisiae accessions. Of particular ecological relevance, the compounds driving the blend differences (acetoin, 2-phenyl ethanol and 3-methyl-1-butanol are known ligands for D. melanogasters chemosensory receptors, and are related to sensory behaviors. Though unable to correlate the genetic and volatile measurements, our data point clear ways forward for behavioral assays aimed at understanding the implications of this variation.

  3. Engineered production of fungal anticancer cyclooligomer depsipeptides in Saccharomyces cerevisiae.

    Science.gov (United States)

    Yu, Dayu; Xu, Fuchao; Zi, Jiachen; Wang, Siyuan; Gage, David; Zeng, Jia; Zhan, Jixun

    2013-07-01

    Two fungal cyclooligomer depsipeptide synthetases(CODSs), BbBEAS (352 kDa) and BbBSLS (348 kDa) from Beauveria bassiana ATCC7159, were reconstituted in Saccharomyces cerevisiae BJ5464-NpgA, leading to the production of the corresponding anticancer natural products, beauvericins and bassianolide, respectively. The titers of beauvericins (33.8 ± 1.4 mg/l) and bassianolide (21.7± 0.1 mg/l) in the engineered S. cerevisiae BJ5464-NpgA strains were comparable to those in the native producer B. bassiana. Feeding D-hydroxyisovaleric acid (D-Hiv) and the corresponding L-amino acid precursors improved the production of beauvericins and bassianolide. However, the high price of D-Hiv limits its application in large-scale production of these cyclooligomer depsipeptides. Alternatively, we engineered another enzyme, ketoisovalerate reductase (KIVR) from B. bassiana, into S. cerevisiae BJ5464-NpgA for enhanced in situ synthesis of this expensive substrate. Co-expression of BbBEAS and KIVR in the yeast led to significant improvement of the production of beauvericins.The total titer of beauvericin and its congeners (beauvericins A-C) was increased to 61.7 ± 3.0 mg/l and reached 2.6-fold of that in the native producer B. bassiana ATCC7159. Supplement of L-Val at 10 mM improved the supply of ketoisovalerate, the substrate of KIVR, which consequently further increased the total titer of beauvericins to 105.8 ± 2.1 mg/l. Using this yeast system,we functionally characterized an unknown CODS from Fusarium venenatum NRRL 26139 as a beauvericin synthetase, which was named as FvBEAS. Our work thus provides a useful approach for functional reconstitution and engineering of fungal CODSs for efficient production of this family of anticancer molecules.

  4. Heterologous expression of cellulase genes in natural Saccharomyces cerevisiae strains.

    Science.gov (United States)

    Davison, Steffi A; den Haan, Riaan; van Zyl, Willem Heber

    2016-09-01

    Enzyme cost is a major impediment to second-generation (2G) cellulosic ethanol production. One strategy to reduce enzyme cost is to engineer enzyme production capacity in a fermentative microorganism to enable consolidated bio-processing (CBP). Ideally, a strain with a high secretory phenotype, high fermentative capacity as well as an innate robustness to bioethanol-specific stressors, including tolerance to products formed during pre-treatment and fermentation of lignocellulosic substrates should be used. Saccharomyces cerevisiae is a robust fermentative yeast but has limitations as a potential CBP host, such as low heterologous protein secretion titers. In this study, we evaluated natural S. cerevisiae isolate strains for superior secretion activity and other industrially relevant characteristics needed during the process of lignocellulosic ethanol production. Individual cellulases namely Saccharomycopsis fibuligera Cel3A (β-glucosidase), Talaromyces emersonii Cel7A (cellobiohydrolase), and Trichoderma reesei Cel5A (endoglucanase) were utilized as reporter proteins. Natural strain YI13 was identified to have a high secretory phenotype, demonstrating a 3.7- and 3.5-fold higher Cel7A and Cel5A activity, respectively, compared to the reference strain S288c. YI13 also demonstrated other industrially relevant characteristics such as growth vigor, high ethanol titer, multi-tolerance to high temperatures (37 and 40 °C), ethanol (10 % w/v), and towards various concentrations of a cocktail of inhibitory compounds commonly found in lignocellulose hydrolysates. This study accentuates the value of natural S. cerevisiae isolate strains to serve as potential robust and highly productive chassis organisms for CBP strain development.

  5. Non-coding RNA prediction and verification in Saccharomyces cerevisiae.

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    Laura A Kavanaugh

    2009-01-01

    Full Text Available Non-coding RNA (ncRNA play an important and varied role in cellular function. A significant amount of research has been devoted to computational prediction of these genes from genomic sequence, but the ability to do so has remained elusive due to a lack of apparent genomic features. In this work, thermodynamic stability of ncRNA structural elements, as summarized in a Z-score, is used to predict ncRNA in the yeast Saccharomyces cerevisiae. This analysis was coupled with comparative genomics to search for ncRNA genes on chromosome six of S. cerevisiae and S. bayanus. Sets of positive and negative control genes were evaluated to determine the efficacy of thermodynamic stability for discriminating ncRNA from background sequence. The effect of window sizes and step sizes on the sensitivity of ncRNA identification was also explored. Non-coding RNA gene candidates, common to both S. cerevisiae and S. bayanus, were verified using northern blot analysis, rapid amplification of cDNA ends (RACE, and publicly available cDNA library data. Four ncRNA transcripts are well supported by experimental data (RUF10, RUF11, RUF12, RUF13, while one additional putative ncRNA transcript is well supported but the data are not entirely conclusive. Six candidates appear to be structural elements in 5' or 3' untranslated regions of annotated protein-coding genes. This work shows that thermodynamic stability, coupled with comparative genomics, can be used to predict ncRNA with significant structural elements.

  6. Local isolate of Saccharomyces cerevisiae as biocompetitive agent of Aspergillus flavus

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    Eni Kusumaningtyas

    2006-12-01

    Full Text Available Aspergillus flavus is a toxigenic fungus that contaminates feed and influences the animal health. Saccharomyces cerevisiae can be used as a biocompetitive agent to control the contamination. The ability of local isolate of S. cerevisiae as a biocompetitive agent for A. flavus was evaluated. A. flavus (30ml was swept on Sabouraud dextrose agar (SDA, while S. cerevisiae was swept on its left and right. Plates were incubated at 28oC for nine days. Lytic activity of S. cerevisiae was detected by pouring its suspension on the centre of the cross streaks of A. flavus. Plates were incubated at 28oC for five days. Growth inhibition of A. flavus by S. cerevisiae was determined by mixing the two fungi on Potato dextrose broth and incubated at 28oC for 24 hours. Total colony of A. flavus were then observed at incubation time of 2, 4, 6 and 24 hours by pour plates method on the SDA plates and incubated on 28oC for two days. Growth of hyphae of A. flavus sweep were inhibited with the swept of S. cerevisiae. The width of A. flavus colony treated with S. cerevisiae is narrower (3,02 cm than that of control ( 4,60 cm. The growth of A. flavus was also inhibited on the centre of cross streak where the S. cerevisiae poured. S. cerevisiae gradually reduced the colony number of A. flavus in the mixed culture of broth fungi ie. 14 x 103 CFU/ml while colony number of control is 80 x 103 CFU/ml. Results showed that S. cerevisiae could be used as biocompetitive agent of A. flavus.

  7. Fluid-phase endocytosis in yeasts other than Saccharomyces cerevisiae.

    Science.gov (United States)

    Fernandez, N; Puente, P; Leal, F

    1990-05-01

    A FITC-dextran internalization assay with Saccharomyces cerevisiae as positive control was used to determine whether fluid-phase endocytosis is a general characteristic of yeasts. Schizosaccharomyces pombe, Pichia polymorpha, Kluyveromyces phaseolosporus, Yarrowia lipolytica and Candida albicans were clearly positive, whereas results obtained with Debaryomyces marama were inconclusive. In all cases internalized FITC-dextran was found to be localized in the vacuoles and the process was always time- and temperature-dependent. Lower eucaryotes, particularly yeasts, appear to have the ability to incorporate substances from the extracellular medium through fluid-phase endocytosis.

  8. Origin of Endogenous DNA Abasic Sites in Saccharomyces cerevisiae

    OpenAIRE

    2003-01-01

    Abasic (AP) sites are among the most frequent endogenous lesions in DNA and present a strong block to replication. In Saccharomyces cerevisiae, an apn1 apn2 rad1 triple mutant is inviable because of its incapacity to repair AP sites and related 3′-blocked single-strand breaks (M. Guillet and S. Boiteux, EMBO J. 21:2833, 2002). Here, we investigated the origin of endogenous AP sites in yeast. Our results show that the deletion of the UNG1 gene encoding the uracil DNA glycosylase suppresses the...

  9. Magnetically altered ethanol fermentation capacity of Saccharomyces cerevisiae

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    Galonja-Corghill Tamara

    2009-01-01

    Full Text Available We studied the effect of static magnetic fields on ethanol production by yeast Saccharomyces cerevisiae 424A (LNH-ST using sugar cane molasses during the fermentation in an enclosed bioreactor. Two static NdFeB magnets were attached to a cylindrical tube reactor with their opposite poles (north to south, creating 150 mT magnetic field inside the reactor. Comparable differences emerged between the results of these two experimental conditions. We found ethanol productivity to be 15% higher in the samples exposed to 150 mT magnetic field.

  10. Directed Evolution towards Increased Isoprenoid Production in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Carlsen, Simon; Nielsen, Michael Lynge; Kielland-Brandt, Morten

    diversity. The most common way of producing these compounds is by organic synthesis. Organic synthesis does however have several disadvantages for production of secondary metabolites such as low yields due to the complex structures, which makes this way of production economically unfeasible. Microbial...... population of S. cerevisiae clones will afterwards be screened using the isoprenoid molecule lycopene as a model compound, hereby enabling the isolation of phenotypes producing higher amounts of isoprenoid. The property making lycopene ideal for screening is its system of 11 conjugated double bonds, which...

  11. Nitrogen catabolite repression of asparaginase II in Saccharomyces cerevisiae.

    OpenAIRE

    Dunlop, P C; Meyer, G M; Roon, R J

    1980-01-01

    The biosynthesis of asparaginase II in Saccharomyces cerevisiae is subject to strong catabolite repression by a variety of nitrogen compounds. In the present study, asparaginase II synthesis was examined in a wild-type yeast strain and in strains carrying gdhA, gdhCR, or gdhCS mutations. The following effects were observed: (i) In the wild-type strain, the biosynthesis of asparaginase II was strongly repressed when either 10 mM ammonium sulfate or various amino acids (10 mM) served as the sou...

  12. Adsorption and Interfacial Electron Transfer of Saccharomyces Cerevisiae

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thanulov

    2003-01-01

    We have studied the adsorption and electron-transfer dynamics of Saccharomyces cerevisiae (yeast) iso-l-cytochrome c adsorbed on Au(lll) electrodes in aqueous phosphate buffer media. This cytochrome possesses a thiol group dos e to the protein surface (Cysl02) suitable for linking the protein...... negative ofthe equilibrium potential of YCC, where the protein is electrochemically functional. The MCS data show tensile differential stress signals when YCC is adsorbed on a gold-coate d MCS, with distinguishable adsorption phases in the time range from

  13. Differential repair of UV damage in Saccharomyces cerevisiae.

    Science.gov (United States)

    Terleth, C; van Sluis, C A; van de Putte, P

    1989-06-26

    Preferential repair of UV-induced damage is a phenomenon by which mammalian cells might enhance their survival. This paper presents the first evidence that preferential repair occurs in the lower eukaryote Saccharomyces cerevisiae. Moreover an unique approach is reported to compare identical sequences present on the same chromosome and only differing in expression. We determined the removal of pyrimidine dimers from two identical alpha-mating type loci and we were able to show that the active MAT alpha locus is repaired preferentially to the inactive HML alpha locus. In a sir-3 mutant, in which both loci are active this preference is not observed.

  14. Metabolic engineering of Saccharomyces cerevisiae for optimizing 3HP production

    DEFF Research Database (Denmark)

    Jensen, Niels Bjerg; Maury, Jerome; Oberg, Fredrik;

    2012-01-01

    and the market for acrylate products exceeds USD 100 billion. As an alternative to oil and gas derived acrylic acid, 3-hydroxypropionic (3HP) acid produced from renewable sources is highly desired, because 3HP can easily be converted into acrylic acid. We are setting out to produce 3HP in yeast Saccharomyces...... cerevisiae. One main reason for selecting Baker's yeast as host organism is that yeast has a high tolerance towards low pH in comparison to bacteria, e.g. E. coli. Hence, it lowers the consumption of base for neutralization of growth media when compared to bacteria. The preferred engineered pathway towards 3...

  15. Electrical stimulation of saccharomyces cerevisiae cultures Estimulação elétrica de células de Saccharomyces cerevisiae

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    Ofelia Q.F. Araújo

    2004-06-01

    Full Text Available Modulation of cell endogenous membrane potential by an external electrical field influences the structure and function of membrane compartments, proteins and lipid bi-layer. In this work, the effects of applied potential on Saccharomyces cerevisiae growth were characterized through simple yet conclusive experiments. Cell growth time profile and cell division were investigated as macroscopic response to the electrical stimulation. Control experiments were conducted under identical conditions except for the absence of applied potential. Through comparative analysis, electrical stimulation was verified to alter cell cycle as smaller sized population was observed, suggesting that a synchrony in cell division was promoted. Power spectral analysis was employed to sustain synchrony enhancement, and mathematical modeling was conducted for determining kinetic growth changes. Monod type kinetic parameters for growth were determined by non-linear regression. The affinity constant (namely kS presented a dependence on applied potential suggesting changes on transport across cell membrane. Electrochemically promoted stress was also verified to inhibit growth as well as to induce changes on cell viability.Modulação do potencial de membrana celular endógeno por um campo elétrico externo influencia a estrutura e função dos compartimentos da membrana, de suas proteínas e da bi-camada lipídica. Neste trabalho, os efeitos da aplicação de potencial no crescimento de Saccharomyces cerevisiae foram caracterizados por experimentos simples, mas conclusivos. O perfil temporal de crescimento celular e a divisão celular foram investigados como respostas macroscópicas ao estímulo elétrico. Experimentos controle foram conduzidos em condições idênticas, exceto pela ausência de potencial aplicado. Através de análise comparativa, verificou-se que o estímulo elétrico alterou o ciclo celular como foi possível observar através da medida da dispersão de

  16. Three New Myrsinol Diterpenes from <em>Euphorbia proliferaem> and Their Neuroprotective Activities

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    Yuanqiang Guo

    2012-08-01

    Full Text Available Three new myrsinol diterpenes were isolated from the roots of<em> em>>Euphorbia proliferaem>. Their structures were elucidated as 2<em>α-O>-isobutyryl-3<em>β>,5<em>α>,7<em>β>,10,15<em>β-penta-O>-acetyl-14<em>α-O>-benzoyl-10,18-dihydromyrsinol (1, 2<em>α-O>-isobutyryl-3<em>β-O>-propion-yl-5<em>α>,7<em>β>,10,15<em>β-tetra-O>-acetyl-10,18-dihydromyrsinol (2, and 2<em>α>,14<em>α-di-O>-benzoyl-3<em>β>,5<em>α>,7<em>β>,10,15<em>β-penta-O>-acetyl-10,18-dihydromyrsinol (3 on the basis of spectroscopic data analyses (IR, ESI-MS, HR-ESI-MS, and 1D and 2D NMR. Their neuroprotective activities were evaluated and compounds 1 and 2 showed neuroprotective effects against MPP+-induced neuronal cell death in SH-SY5Y cells.

  17. Effects of low-intensity ultrasound on the growth, cell membrane permeability and ethanol tolerance of Saccharomyces cerevisiae.

    Science.gov (United States)

    Dai, Chunhua; Xiong, Feng; He, Ronghai; Zhang, Weiwei; Ma, Haile

    2017-05-01

    Effects of low-intensity ultrasound (at different frequency, treatment time and power) on Saccharomyces cerevisiae in different growth phase were evaluated by the biomass in the paper. In addition, the cell membrane permeability and ethanol tolerance of sonicated Saccharomyces cerevisiae were also researched. The results revealed that the biomass of Saccharomyces cerevisiae increased by 127.03% under the optimum ultrasonic conditions such as frequency 28kHz, power 140W/L and ultrasonic time 1h when Saccharomyces cerevisiae cultured to the latent anaphase. And the membrane permeability of Saccharomyces cerevisiae in latent anaphase enhanced by ultrasound, resulting in the augment of extracellular protein, nucleic acid and fructose-1,6-diphosphate (FDP) contents. In addition, sonication could accelerate the damage of high concentration alcohol to Saccharomyces cerevisiae although the ethanol tolerance of Saccharomyces cerevisiae was not affected significantly by ultrasound.

  18. Production of recombinant Agaricus bisporus tyrosinase in Saccharomyces cerevisiae cells.

    Science.gov (United States)

    Lezzi, Chiara; Bleve, Gianluca; Spagnolo, Stefano; Perrotta, Carla; Grieco, Francesco

    2012-12-01

    It has been demonstrated that Agaricus bisporus tyrosinase is able to oxidize various phenolic compounds, thus being an enzyme of great importance for a number of biotechnological applications. The tyrosinase-coding PPO2 gene was isolated by reverse-transcription polymerase chain reaction (RT-PCR) using total RNA extracted from the mushroom fruit bodies as template. The gene was sequenced and cloned into pYES2 plasmid, and the resulting pY-PPO2 recombinant vector was then used to transform Saccharomyces cerevisiae cells. Native polyacrylamide gel electrophoresis followed by enzymatic activity staining with L-3,4-dihydroxyphenylalanine (L-DOPA) indicated that the recombinant tyrosinase is biologically active. The recombinant enzyme was overexpressed and biochemically characterized, showing that the catalytic constants of the recombinant tyrosinase were higher than those obtained when a commercial tyrosinase was used, for all the tested substrates. The present study describes the recombinant production of A. bisporus tyrosinase in active form. The produced enzyme has similar properties to the one produced in the native A. bisporus host, and its expression in S. cerevisiae provides good potential for protein engineering and functional studies of this important enzyme.

  19. Structure of the Glycosyltransferase Ktr4p from Saccharomyces cerevisiae.

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    Dominik D D Possner

    Full Text Available In the yeast Saccharomyces cerevisiae, members of the Kre2/Mnt1 protein family have been shown to be α-1,2-mannosyltransferases or α-1,2-mannosylphosphate transferases, utilising an Mn2+-coordinated GDP-mannose as the sugar donor and a variety of mannose derivatives as acceptors. Enzymes in this family are localised to the Golgi apparatus, and have been shown to be involved in both N- and O-linked glycosylation of newly-synthesised proteins, including cell wall glycoproteins. Our knowledge of the nine proteins in this family is however very incomplete at present. Only one family member, Kre2p/Mnt1p, has been studied by structural methods, and three (Ktr4p, Ktr5p, Ktr7p are completely uncharacterised and remain classified only as putative glycosyltransferases. Here we use in vitro enzyme activity assays to provide experimental confirmation of the predicted glycosyltransferase activity of Ktr4p. Using GDP-mannose as the donor, we observe activity towards the acceptor methyl-α-mannoside, but little or no activity towards mannose or α-1,2-mannobiose. We also present the structure of the lumenal catalytic domain of S. cerevisiae Ktr4p, determined by X-ray crystallography to a resolution of 2.2 Å, and the complex of the enzyme with GDP to 1.9 Å resolution.

  20. Characteristics of Zn2+ Biosorption by Saccharomyces cerevisiae

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Objective To investigate the characteristics of Zn2+ biosorption and the release of cations during the process of Zn2+biosorption by intact cells of Saccharomyces cerevisiae. Methods The batch adsorption test was used to study the biosorption equilibrium and isotherm. Zn2+ concentration was measured with atomic adsorption spectrophotometer (AAS) AAS 6.Vario. Results When the initial concentration of Zn2+ ranged between 0.08 and 0.8 mmol/L, the initial pH was natural (about 5.65), the sorbent concentration was about 1 g/L and the capacity of Zn2+ biosorption was from 74.8 to 654.8 μmol/g. The pH value increased by 0.55-1.28 and the intracellular cations (K+, Mg2+, Na+, Ca2+) of the cells were released during the process of Zn2+ biosorption. Conclusion Ion exchange was one of the mechanisms for Zn2+ biosorption. The biomass of Saccharomyces cerevisiae is a potential biosorbent for the removal of Zn2+ from aqueous solution. More work needs to be done before putting it into practical application.

  1. Long-chain alkane production by the yeast Saccharomyces cerevisiae.

    Science.gov (United States)

    Buijs, Nicolaas A; Zhou, Yongjin J; Siewers, Verena; Nielsen, Jens

    2015-06-01

    In the past decade industrial-scale production of renewable transportation biofuels has been developed as an alternative to fossil fuels, with ethanol as the most prominent biofuel and yeast as the production organism of choice. However, ethanol is a less efficient substitute fuel for heavy-duty and maritime transportation as well as aviation due to its low energy density. Therefore, new types of biofuels, such as alkanes, are being developed that can be used as drop-in fuels and can substitute gasoline, diesel, and kerosene. Here, we describe for the first time the heterologous biosynthesis of long-chain alkanes by the yeast Saccharomyces cerevisiae. We show that elimination of the hexadecenal dehydrogenase Hfd1 and expression of a redox system are essential for alkane biosynthesis in yeast. Deletion of HFD1 together with expression of an alkane biosynthesis pathway resulted in the production of the alkanes tridecane, pentadecane, and heptadecane. Our study provides a proof of principle for producing long-chain alkanes in the industrial workhorse S. cerevisiae, which was so far limited to bacteria. We anticipate that these findings will be a key factor for further yeast engineering to enable industrial production of alkane based drop-in biofuels, which can allow the biofuel industry to diversify beyond bioethanol.

  2. Lactose fermentation by engineered Saccharomyces cerevisiae capable of fermenting cellobiose.

    Science.gov (United States)

    Liu, Jing-Jing; Zhang, Guo-Chang; Oh, Eun Joong; Pathanibul, Panchalee; Turner, Timothy L; Jin, Yong-Su

    2016-09-20

    Lactose is an inevitable byproduct of the dairy industry. In addition to cheese manufacturing, the growing Greek yogurt industry generates excess acid whey, which contains lactose. Therefore, rapid and efficient conversion of lactose to fuels and chemicals would be useful for recycling the otherwise harmful acid whey. Saccharomyces cerevisiae, a popular metabolic engineering host, cannot natively utilize lactose. However, we discovered that an engineered S. cerevisiae strain (EJ2) capable of fermenting cellobiose can also ferment lactose. This finding suggests that a cellobiose transporter (CDT-1) can transport lactose and a β-glucosidase (GH1-1) can hydrolyze lactose by acting as a β-galactosidase. While the lactose fermentation by the EJ2 strain was much slower than the cellobiose fermentation, a faster lactose-fermenting strain (EJ2e8) was obtained through serial subcultures on lactose. The EJ2e8 strain fermented lactose with a consumption rate of 2.16g/Lh. The improved lactose fermentation by the EJ2e8 strain was due to the increased copy number of cdt-1 and gh1-1 genes. Looking ahead, the EJ2e8 strain could be exploited for the production of other non-ethanol fuels and chemicals from lactose through further metabolic engineering.

  3. Metabolomic approach for improving ethanol stress tolerance in Saccharomyces cerevisiae.

    Science.gov (United States)

    Ohta, Erika; Nakayama, Yasumune; Mukai, Yukio; Bamba, Takeshi; Fukusaki, Eiichiro

    2016-04-01

    The budding yeast Saccharomyces cerevisiae is widely used for brewing and ethanol production. The ethanol sensitivity of yeast cells is still a serious problem during ethanol fermentation, and a variety of genetic approaches (e.g., random mutant screening under selective pressure of ethanol) have been developed to improve ethanol tolerance. In this study, we developed a strategy for improving ethanol tolerance of yeast cells based on metabolomics as a high-resolution quantitative phenotypic analysis. We performed gas chromatography-mass spectrometry analysis to identify and quantify 36 compounds on 14 mutant strains including knockout strains for transcription factor and metabolic enzyme genes. A strong relation between metabolome of these mutants and their ethanol tolerance was observed. Data mining of the metabolomic analysis showed that several compounds (such as trehalose, valine, inositol and proline) contributed highly to ethanol tolerance. Our approach successfully detected well-known ethanol stress related metabolites such as trehalose and proline thus, to further prove our strategy, we focused on valine and inositol as the most promising target metabolites in our study. Our results show that simultaneous deletion of LEU4 and LEU9 (leading to accumulation of valine) or INM1 and INM2 (leading to reduction of inositol) significantly enhanced ethanol tolerance. This study shows the potential of the metabolomic approach to identify target genes for strain improvement of S. cerevisiae with higher ethanol tolerance.

  4. Phosphite disrupts the acclimation of Saccharomyces cerevisiae to phosphate starvation.

    Science.gov (United States)

    McDonald, A E; Niere, J O; Plaxton, W C

    2001-11-01

    The influence of phosphite (H2PO3-) on the response of Saccharomyces cerevisiae to orthophosphate (HPO4(2-); Pi) starvation was assessed. Phosphate-repressible acid phosphatase (rAPase) derepression and cell development were abolished when phosphate-sufficient (+Pi) yeast were subcultured into phosphate-deficient (-Pi) media containing 0.1 mM phosphite. By contrast, treatment with 0.1 mM phosphite exerted no influence on rAPase activity or growth of +Pi cells. 31P NMR spectroscopy revealed that phosphite is assimilated and concentrated by yeast cultured with 0.1 mM phosphite, and that the levels of sugar phosphates, pyrophosphate, and particularly polyphosphate were significantly reduced in the phosphite-treated -Pi cells. Examination of phosphite's effects on two PHO regulon mutants that constitutively express rAPase indicated that (i) a potential target for phosphite's action in -Pi yeast is Pho84 (plasmalemma high-affinity Pi transporter and component of a putative phosphate sensor-complex), and that (ii) an additional mechanism exists to control rAPase expression that is independent of Pho85 (cyclin-dependent protein kinase). Marked accumulation of polyphosphate in the delta pho85 mutant suggested that Pho85 contributes to the control of polyphosphate metabolism. Results are consistent with the hypothesis that phosphite obstructs the signaling pathway by which S. cerevisiae perceives and responds to phosphate deprivation at the molecular level.

  5. The evolution of gene expression QTL in Saccharomyces cerevisiae.

    Directory of Open Access Journals (Sweden)

    James Ronald

    Full Text Available Understanding the evolutionary forces that influence patterns of gene expression variation will provide insights into the mechanisms of evolutionary change and the molecular basis of phenotypic diversity. To date, studies of gene expression evolution have primarily been made by analyzing how gene expression levels vary within and between species. However, the fundamental unit of heritable variation in transcript abundance is the underlying regulatory allele, and as a result it is necessary to understand gene expression evolution at the level of DNA sequence variation. Here we describe the evolutionary forces shaping patterns of genetic variation for 1206 cis-regulatory QTL identified in a cross between two divergent strains of Saccharomyces cerevisiae. We demonstrate that purifying selection against mildly deleterious alleles is the dominant force governing cis-regulatory evolution in S. cerevisiae and estimate the strength of selection. We also find that essential genes and genes with larger codon bias are subject to slightly stronger cis-regulatory constraint and that positive selection has played a role in the evolution of major trans-acting QTL.

  6. Investigation of the Best Saccharomyces cerevisiae Growth Condition

    Science.gov (United States)

    Salari, Roshanak; Salari, Rosita

    2017-01-01

    Introduction Saccharomyces cerevisiae is known as one of the useful yeasts which are utilized in baking and other industries. It can be easily cultured at an economic price. Today the introduction of safe and efficient carriers is being considered. Due to its generally round shape, and the volume that is enclosed by its membrane and cell wall, it is used to encapsulate active materials to protect them from degradation or to introduce a sustained release drug delivery system. Providing the best conditions in order to achieve the best morphological properties of Saccharomyces cerevisiae as a carrier. Methods In this research, the most suitable growth condition of yeast cells which provides the best size for use as drug carriers was found by a bioreactor in a synthetic culture medium. Yeast cell reproduction and growth curves were obtained, based on pour plate colony counting data and UV/Visible sample absorption at 600 nm. Yeast cell growth patterns and growth rates were determined by Matlab mathematical software. Results Results showed that pH=4 and dissolving oxygen (DO) 5% was the best condition for yeast cells to grow and reproduce. This condition also provided the largest size (2 × 3 μ) yeast cells. Conclusion Owing to the yeast cells’ low-cost production and their structural characteristics, they could be used as potent drug carriers. Funding This work was supported by a grant from the Vice Chancellor of Research of Mashhad University of Medical Sciences. PMID:28243411

  7. CRISPR-Cas9 Genome Engineering in Saccharomyces cerevisiae Cells.

    Science.gov (United States)

    Ryan, Owen W; Poddar, Snigdha; Cate, Jamie H D

    2016-06-01

    This protocol describes a method for CRISPR-Cas9-mediated genome editing that results in scarless and marker-free integrations of DNA into Saccharomyces cerevisiae genomes. DNA integration results from cotransforming (1) a single plasmid (pCAS) that coexpresses the Cas9 endonuclease and a uniquely engineered single guide RNA (sgRNA) expression cassette and (2) a linear DNA molecule that is used to repair the chromosomal DNA damage by homology-directed repair. For target specificity, the pCAS plasmid requires only a single cloning modification: replacing the 20-bp guide RNA sequence within the sgRNA cassette. This CRISPR-Cas9 protocol includes methods for (1) cloning the unique target sequence into pCAS, (2) assembly of the double-stranded DNA repair oligonucleotides, and (3) cotransformation of pCAS and linear repair DNA into yeast cells. The protocol is technically facile and requires no special equipment. It can be used in any S. cerevisiae strain, including industrial polyploid isolates. Therefore, this CRISPR-Cas9-based DNA integration protocol is achievable by virtually any yeast genetics and molecular biology laboratory.

  8. Atividade de nanoformulações de Melaleuca alternifolia e terpinen-4-ol em isolados de Rhodococcus equi

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    L. Sagave

    2015-02-01

    Full Text Available Rhodococcus equi é o agente etiológico da rodococose equina, importante doença respiratória de potros. Especialmente na última década, a emergência de cepas resistentes aos antimicrobianos empregados no tratamento da rodococose tem sido relatada. Nesse sentido, há a necessidade de estudos envolvendo terapias alternativas e novas tecnologias, incluindo o uso de plantas medicinais e nanotecnologia. Neste trabalho utilizou-se Melaleuca alternifolia nas seguintes formulações: óleo livre, nanocápsula, nanoemulsão e a combinação de óleo livre com nanocápsula e com nanoemulsão, além do seu composto majoritário, terpinen-4-ol, a fim de verificar a atividade antimicrobiana frente a isolados de R. equi de diferentes origens. Utilizou-se o método de microdiluição em caldo na determinação das concentrações inibitória mínima (CIM e bactericida mínima (CBM das diferentes formulações frente aos isolados (n=24. Verificou-se baixo potencial para atividade antibacteriana de M. alternifolia na formulação de óleo livre. Todavia, essa atividade foi potencializada quando se incorporou o óleo essencial às nanoformulações. O composto terpinen-4-ol demonstrou potencial atividade antibacteriana quando incorporado ao óleo essencial e quando utilizado isoladamente. Verificou-se que tanto M. alternifolia quanto terpinen-4-ol testados possuem atividade antimicrobiana contra isolados de R. equi, sugerindo seu emprego em estudos avaliando seu potencial para o tratamento da rodococose.

  9. Avaliação da contaminação bacteriana em desinfetantes de uso domiciliar

    Directory of Open Access Journals (Sweden)

    Miyagi Fumie

    2000-01-01

    Full Text Available OBJETIVO: Avaliar desinfetantes de uso domiciliar, identificando a presença de bactérias contaminantes, e conhecer o nível de tolerância dessas bactérias ao cloreto de benzalcônio. MÉTODOS: Foram adquiridas aleatoriamente no comércio da região metropolitana de São Paulo, SP, Brasil, 52 amostras de desinfetantes de uso domiciliar para análise quanto à presença de bactérias contaminantes. O nível de tolerância dessas bactérias ao cloreto de benzalcônio foi determinado pelo método da macrodiluição em caldo. RESULTADOS: De 52 amostras, 16 (30,77% estavam contaminadas por bactérias Gram negativas, com contagens variando entre 10(4 e 10(6 UFC/ml. Esses contaminantes foram identificados como Alcaligenes xylosoxidans, Burkholderia cepacia e Serratia marcescens. As Concentrações Inibitórias Mínimas (CIM: mg/ml do cloreto de benzalcônio para S. marcescens, A. xylosoxidans e B. cepacia foram: 2,48, 1,23 e 0,30, respectivamente. CONCLUSÕES Os desinfetantes de uso domiciliar à base de compostos de amônio quaternário são passíveis de contaminação por bactérias. As CIM do cloreto de benzalcônio para as bactérias contaminantes estavam abaixo das concentrações do princípio ativo presente nos desinfetantes, indicando que a tolerância ao biocida não é estável, podendo ser perdida com o cultivo das bactérias em meios de cultura sem o biocida.

  10. Avaliação da contaminação bacteriana em desinfetantes de uso domiciliar

    Directory of Open Access Journals (Sweden)

    Fumie Miyagi

    2000-10-01

    Full Text Available OBJETIVO: Avaliar desinfetantes de uso domiciliar, identificando a presença de bactérias contaminantes, e conhecer o nível de tolerância dessas bactérias ao cloreto de benzalcônio. MÉTODOS: Foram adquiridas aleatoriamente no comércio da região metropolitana de São Paulo, SP, Brasil, 52 amostras de desinfetantes de uso domiciliar para análise quanto à presença de bactérias contaminantes. O nível de tolerância dessas bactérias ao cloreto de benzalcônio foi determinado pelo método da macrodiluição em caldo. RESULTADOS: De 52 amostras, 16 (30,77% estavam contaminadas por bactérias Gram negativas, com contagens variando entre 10(4 e 10(6 UFC/ml. Esses contaminantes foram identificados como Alcaligenes xylosoxidans, Burkholderia cepacia e Serratia marcescens. As Concentrações Inibitórias Mínimas (CIM: mg/ml do cloreto de benzalcônio para S. marcescens, A. xylosoxidans e B. cepacia foram: 2,48, 1,23 e 0,30, respectivamente. CONCLUSÕES Os desinfetantes de uso domiciliar à base de compostos de amônio quaternário são passíveis de contaminação por bactérias. As CIM do cloreto de benzalcônio para as bactérias contaminantes estavam abaixo das concentrações do princípio ativo presente nos desinfetantes, indicando que a tolerância ao biocida não é estável, podendo ser perdida com o cultivo das bactérias em meios de cultura sem o biocida.

  11. Cultura lática mista com potencial de aplicação como cultura iniciadora em produtos cárneos

    Directory of Open Access Journals (Sweden)

    BALDUINO Rosicler

    1999-01-01

    Full Text Available Bactérias viáveis adicionadas em produtos cárneos com a finalidade de melhorar a qualidade sanitária, as características sensoriais e reduzir nitritos, são denominadas de cultura iniciadora. Pode ser constituída de cultura pura ou mista com habilidade em produzir substâncias antimicrobianas como ácido lático e bacteriocinas, capazes de inibir microrganismos indesejáveis ao produto alimentício. Neste trabalho, avaliou-se algumas associações entre bactérias láticas, Lactobacillus, Pediococcus e Enterococcus, visando obter culturas láticas com habilidade bioquímica para fermentação homolática; alta viabilidade celular; tolerância ao sais NaCl e NaNO2; capacidade de reduzir nitritos e inibir patógenos como S. aureus; Salmonella spp. e E. coli enteropatogênica. Os cultivos foram desenvolvidos em MRS, incubados a 37ºC por 48 horas. O ácido lático foi determinado por Cromatografia Líquida de Alta Eficiência. Nitrito residual foi determinado por espectrofotometria. A fermentação homolática com melhor produção de ácido lático (4,61% e alta viabilidade celular (3 x 10(15 UFC/mL foi obtida pela cultura constituída de L. curvatus, L. plantarum, P. acidilactici e E. faecium . A cultura mista selecionada apresentou alta viabilidade celular (1x10(14 UFC/mL, mesmo em altas concentrações de NaCl e NaNO2. O caldo fermentado apresentou 99% de redução do nitrito inicial. A cultura lática mista selecionada inibiu S. aureus, Salmonella spp. e E. coli em ágar BHI. Em lingüiça frescal, observou-se a diminuição da contagem de S. aureus e coliformes totais em relação ao controle. Salmonella spp. não foi detectada nas amostras testadas. Os resultados mostram a possibilidade de aplicação da cultura mista selecionada como cultura iniciadora em produtos cárneos.

  12. Avaliação de diferentes meios de enriquecimento para o isolamento de Salmonella, ocorentes em água de esgoto

    Directory of Open Access Journals (Sweden)

    Ernesto Hofer

    1972-01-01

    Full Text Available Examinando-se 158 amostras de águas cloacais, provenientes de uma estação de tratamento e de uma elevatória de esgotos, localizadas na cidade do Rio de Janeiro, fêz-se uma avaliação da eficiência de quatro meios de enriquecimento para Salmonella. Os meios empregados foram o caldo tetrationato, segundo Kauffmann, o meio de Rappaport e duas modificações deste meio, previamente descritas. Os resultados encontrados, evidenciaram a superioridade de um dos meios modificados da Rappaport, em que se fez a substituição do verde malaquiata por outro corante bacteriostático (Metachromgelb II RD e com a inclusão de tetrationato, à fórmula original. A maior eficiência assinalada para este meio se baseou nos resultados obtidos do enriquecimento dos diferentes grupos sorológicos e particularmente dos quinze sorotipos mais incidentes de Salmonella enteritidis, na presente investigação.Four enrichment broths (Kauffmann's tetrathionate broth Rappaport's medium an two modifications introduced in original formula of Rappaport broth's previously described, were compared for efficiency of detection of Salmonella from 158 sewage samples, obtained from two treatment sewage stations. In comparative trials, the modified Rappaport medium with tetrathionate and metachromgelb II RD, was highly effective for the recovery of a wide range of Salmonella enteritidis serotypes.

  13. Neonatal Phosphate Nutrition Alters <em>in em>Vivo> and <em>in em>Vitro> Satellite Cell Activity in Pigs

    Directory of Open Access Journals (Sweden)

    Chad H. Stahl

    2012-05-01

    Full Text Available Satellite cell activity is necessary for postnatal skeletal muscle growth. Severe phosphate (PO4 deficiency can alter satellite cell activity, however the role of neonatal PO4 nutrition on satellite cell biology remains obscure. Twenty-one piglets (1 day of age, 1.8 ± 0.2 kg BW were pair-fed liquid diets that were either PO4 adequate (0.9% total P, supra-adequate (1.2% total P in PO4 requirement or deficient (0.7% total P in PO4 content for 12 days. Body weight was recorded daily and blood samples collected every 6 days. At day 12, pigs were orally dosed with BrdU and 12 h later, satellite cells were isolated. Satellite cells were also cultured <em>in vitroem> for 7 days to determine if PO4 nutrition alters their ability to proceed through their myogenic lineage. Dietary PO4 deficiency resulted in reduced (<em>P> < 0.05 sera PO4 and parathyroid hormone (PTH concentrations, while supra-adequate dietary PO4 improved (<em>P> < 0.05 feed conversion efficiency as compared to the PO4 adequate group. <em>In vivoem> satellite cell proliferation was reduced (<em>P> < 0.05 among the PO4 deficient pigs, and these cells had altered <em>in vitroem> expression of markers of myogenic progression. Further work to better understand early nutritional programming of satellite cells and the potential benefits of emphasizing early PO4 nutrition for future lean growth potential is warranted.

  14. Inactivation of Saccharomyces cerevisiae suspended in orange juice using high-intensity pulsed electric fields.

    Science.gov (United States)

    Elez-Martínez, Pedro; Escolà-Hernández, Joan; Soliva-Fortuny, Robert C; Martín-Belloso, Olga

    2004-11-01

    Saccharomyces cerevisiae is often associated with the spoilage of fruit juices. The purpose of this study was to evaluate the effect of high-intensity pulsed electric field (HIPEF) treatment on the survival of S. cerevisiae suspended in orange juice. Commercial heat-sterilized orange juice was inoculated with S. cerevisiae (CECT 1319) (10(8) CFU/ml) and then treated by HIPEFs. The effects of HIPEF parameters (electric field strength, treatment time, pulse polarity, frequency, and pulse width) were evaluated and compared to those of heat pasteurization (90 degrees C/min). In all of the HIPEF experiments, the temperature was kept below 39 degrees C. S. cerevisiae cell damage induced by HIPEF treatment was observed by electron microscopy. HIPEF treatment was effective for the inactivation of S. cerevisiae in orange juice at pasteurization levels. A maximum inactivation of a 5.1-log (CFU per milliliter) reduction was achieved after exposure of S. cerevisiae to HIPEFs for 1,000 micros (4-micros pulse width) at 35 kV/cm and 200 Hz in bipolar mode. Inactivation increased as both the field strength and treatment time increased. For the same electric field strength and treatment time, inactivation decreased when the frequency and pulse width were increased. Electric pulses applied in the bipolar mode were more effective than those in the monopolar mode for destroying S. cerevisiae. HIPEF processing inactivated S. cerevisiae in orange juice, and the extent of inactivation was similar to that obtained during thermal pasteurization. HIPEF treatments caused membrane damage and had a profound effect on the intracellular organization of S. cerevisiae.

  15. Correlation between Saccharomyces cerevisiae DNA in intestinal mucosal samples and anti-Saccharomyces cerevisiae antibodies in serum of patients with IBD

    Institute of Scientific and Technical Information of China (English)

    RC Mallant-Hent; M Mooij; BME von Blomberg; RK Linskens; AA van Bodegraven; PHM Savelkoul

    2006-01-01

    AIM: To investigate the correlation between ASCA and presence of mucosal S. cerevisiae DNA in a population of CD, ulcerative colitis (UC) patients and controls.METHODS: S. cerevisiae-specific primers and a fluorescent probe were designed for a 5' exonuclease real time PCR (TaqManTM) assay, which is a homogenous system using a fluorescent-labelled probe for the detection of PCR product in real time. We analyzed the relation of the PCR results with the ASCA findings in a group of 76inflammatory bowel disease (IBD) patients (31 CD, 45UC) and 22 healthy controls (HC).RESULTS: ASCA (IgA or IgG) were positive in 19 (61%)patients with CD, 12 (27%) with UC and none of the HC. PCR amplification was inhibited and excluded from the final results in 10 (22%) UC patients, 7 (22%) CD patients, and 6 (30%) HC. In only 15 of the mucosal samples, S. cerevisiae DNA was detected by real time PCR, including 7 (29%) in CD, 7 (19%) in UC, 1 (6%)in HC. In 4 CD and in 4 UC patients, ASCA and mucosal S. cerevisiae were positive. Mucosal S. cerevisiae was present in combination with negative ASCA IgA and IgG in 3 UC, and 3 CD patients.CONCLUSION: We conclude that since the presence of S. cerevisiae in colonic mucosal biopsy specimens is very rare, ASCA is unlikely to be explained by continuous exposure to S. cerevisiae in the mucosa. Therefore,ASCA formation must occur earlier in life and levels remain relatively stable thereafter in immunological susceptible persons.

  16. Overexpression of Sbe2p, a Golgi Protein, Results in Resistance to Caspofungin in Saccharomyces cerevisiae

    OpenAIRE

    Osherov, Nir; May, Gregory S.; Albert, Nathaniel D.; Kontoyiannis, D. P.

    2002-01-01

    Caspofungin inhibits the synthesis of 1, 3-β-d-glucan, an essential cell wall target in fungi. Genetic studies in the model yeast Saccharomyces cerevisiae have shown that mutations in FKS1 and FKS2 genes result in caspofungin resistance. However, direct demonstration of the role of gene overexpression in caspofungin resistance has been lacking. We transformed wild-type S. cerevisiae with an S. cerevisiae URA3-based GAL1 cDNA library and selected transformants in glucose synthetic complete pla...

  17. Constituents from <em>Vigna em>vexillata> and Their Anti-Inflammatory Activity

    Directory of Open Access Journals (Sweden)

    Guo-Feng Chen

    2012-08-01

    Full Text Available The seeds of <em>Vigna em>genus are important food resources and there have already been many reports regarding their bioactivities. In our preliminary bioassay, the chloroform layer of methanol extracts of<em> V. vexillata em>demonstrated significant anti-inflammatory bioactivity. Therefore, the present research is aimed to purify and identify the anti-inflammatory principles of <em>V. vexillataem>. One new sterol (1 and two new isoflavones (2,3 were reported from the natural sources for the first time and their chemical structures were determined by the spectroscopic and mass spectrometric analyses. In addition, 37 known compounds were identified by comparison of their physical and spectroscopic data with those reported in the literature. Among the isolates, daidzein (23, abscisic acid (25, and quercetin (40 displayed the most significant inhibition of superoxide anion generation and elastase release.

  18. Regulation of xylose metabolism in recombinant Saccharomyces cerevisiae

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    Penttilä Merja

    2008-06-01

    Full Text Available Abstract Background Considerable interest in the bioconversion of lignocellulosic biomass into ethanol has led to metabolic engineering of Saccharomyces cerevisiae for fermentation of xylose. In the present study, the transcriptome and proteome of recombinant, xylose-utilising S. cerevisiae grown in aerobic batch cultures on xylose were compared with those of glucose-grown cells both in glucose repressed and derepressed states. The aim was to study at the genome-wide level how signalling and carbon catabolite repression differ in cells grown on either glucose or xylose. The more detailed knowledge whether xylose is sensed as a fermentable carbon source, capable of catabolite repression like glucose, or is rather recognised as a non-fermentable carbon source is important for further engineering this yeast for more efficient anaerobic fermentation of xylose. Results Genes encoding respiratory proteins, proteins of the tricarboxylic acid and glyoxylate cycles, and gluconeogenesis were only partially repressed by xylose, similar to the genes encoding their transcriptional regulators HAP4, CAT8 and SIP1-2 and 4. Several genes that are repressed via the Snf1p/Mig1p-pathway during growth on glucose had higher expression in the cells grown on xylose than in the glucose repressed cells but lower than in the glucose derepressed cells. The observed expression profiles of the transcription repressor RGT1 and its target genes HXT2-3, encoding hexose transporters suggested that extracellular xylose was sensed by the glucose sensors Rgt2p and Snf3p. Proteome analyses revealed distinct patterns in phosphorylation of hexokinase 2, glucokinase and enolase isoenzymes in the xylose- and glucose-grown cells. Conclusion The results indicate that the metabolism of yeast growing on xylose corresponds neither to that of fully glucose repressed cells nor that of derepressed cells. This may be one of the major reasons for the suboptimal fermentation of xylose by

  19. Padrão de sensibilidade de 117 amostras clínicas de Staphylococcus aureus isoladas em 12 hospitais

    Directory of Open Access Journals (Sweden)

    Farias W.V.L.

    1997-01-01

    Full Text Available OBJETIVO. Avaliar o padrão de sensibilidade in vitro de amostras clínicas de Staphylococcus aureus sensíveis (OSSA e resistentes à oxacilina (ORSA a outros antimicrobianos que podem ser utilizados no tratamento de infecções estafilocócicas. MATERIAL E MÉTODO. Foram analisadas 117 amostras clínicas de S. aureus isoladas em vários hospitais de São Paulo. Também foram incluídas amostras isoladas em Campinas, SP, e João Pessoa, PB. A avaliação da sensibilidade in vitro aos antimicrobianos foi realizada pela técnica de microdiluição em caldo, utilizando os procedimentos preconizados pelo National Committee for Clinical Laboratory Standards (NCCLS. Foi avaliada a concentração inibitória mínima (MIC para 24 antimicrobianos da classe dos beta-lactâmicos, fluoroquinolonas, aminoglicosídeos, glicopeptídeos, macrolídeos, lincosaminas e estreptograminas. Foram avaliadas tanto drogas disponíveis comercialmente quanto as que ainda se encontram em fase de pesquisa. A resistência cruzada entre dez fluoroquinolonas foi avaliada em 24 amostras. RESULTADOS. Os glicopeptídeos, o RP-59500 e a mupirocina foram os antimicrobianos que apresentaram maior atividade in vitro contra amostras de ORSA (100% sensibilidade. Oitenta e sete por cento das amostras de OSSA foram sensíveis à ciprofloxacina (MIC50 0,25mig/mL, enquanto que, para os ORSA, a sensibilidade foi de apenas 38% (MIC50 >4mig/mL. A resistência cruzada para as fluoroquinolonas foi observada mesmo para drogas não disponíveis comercialmente. As fluoroquinolonas que permaneceram ativas contra amostras resistentes à ciprofloxacina (clinafloxacina e WIN-57.273 apresentaram MICs 8 a 64 vezes mais elevados que as amostras sensíveis à ciprofloxacina, sugerindo que, quando lançadas na prática clínica, esses MICs possam se elevar ainda mais, inviabilizando o uso clínico desses compostos. CONCLUSÃO. Os resultados do presente estudo mostraram uma alta taxa de resistência a

  20. The Antimicrobial Efficacy of <em>Elaeis guineensisem>: Characterization, <em>in Vitroem> and <em>in Vivoem> Studies

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    Sreenivasan Sasidharan

    2012-04-01

    Full Text Available The urgent need to treat multi-drug resistant pathogenic microorganisms in chronically infected patients has given rise to the development of new antimicrobials from natural resources. We have tested <em>Elaeis guineensis em>Jacq> em>(Arecaceae methanol extract against a variety of bacterial, fungal and yeast strains associated with infections. Our studies have demonstrated that <em>E. guineensisem> exhibits excellent antimicrobial activity <em>in vitroem> and <em>in vivoem> against the bacterial and fungal strains tested. A marked inhibitory effect of the <em>E. guineensisem> extracts was observed against <em>C. albicansem> whereby <em>E. guineensisem> extract at ½, 1, or 2 times the MIC significantly inhibited <em>C. albicansem> growth with a noticeable drop in optical density (OD of the bacterial culture. This finding confirmed the anticandidal activity of the extract on <em>C. albicansem>. Imaging using scanning (SEM and transmission (TEM electron microscopy was done to determine the major alterations in the microstructure of the extract-treated <em>C. albicansem>. The main abnormalities noted via SEM and TEM studies were the alteration in morphology of the yeast cells. <em>In vivoem> antimicrobial activity was studies in mice that had been inoculated with <em>C. albicansem> and exhibited good anticandidal activity. The authors conclude that the extract may be used as a candidate for the development of anticandidal agent.<em> em>

  1. Avaliação de microrganismos antagônicos, Saccharomyces cerevisiae e Bacillus subtilis para o controle de Penicillium digitatum

    Directory of Open Access Journals (Sweden)

    Katia Cristina Kupper

    2013-06-01

    Full Text Available Os frutos cítricos são afetados por diversas doenças, especialmente as fúngicas, as quais afetam a produtividade e a qualidade, principalmente quando se visa ao mercado de frutas frescas, seja para o mercado interno, seja para a exportação. Dentre as doenças fúngicas que ocorrem na fase de pós-colheita, destaca-se o bolor verde, causado por Penicillium digitatum. As medidas de controle baseiam-se, principalmente, no tratamento de frutos com diferentes combinações de fungicidas no packing-house. Devido às restrições quanto à presença de resíduos de fungicidas em frutos de citros e ao crescente desenvolvimento de linhagens resistentes dos patógenos a tais fungicidas, torna-se necessária a busca de alternativas de controle, como o controle biológico. Portanto, este trabalho teve por objetivos: (i verificar o efeito antagônico de agentes de controle biológico (ACBs, sendo 06 isolados de Saccharomyces cerevisiae e 13 isolados de Bacillus subtilis contra P. digitatum; (ii estudar as interações in vitro entre ACBs e o fitopatógeno; (iii verificar o efeito da integração dos antagonistas com bicarbonato de sódio e cera de carnaúba no controle do bolor verde. Os resultados mostraram que a maioria dos isolados bacterianos e todos os isolados de levedura inibiram o crescimento micelial do fitopatógeno. Somente um isolado de Bacillus subtilis (ACB-84 foi capaz de inibir a germinação de P. digitatum com 72% de inibição, enquanto ACB-K1 e ACB-CR1 (S. cerevisiae foram os mais eficientes com inibições de 78 e 85,7%, respectivamente; a adição de sacarose (a 0,5% favoreceu ainda mais a inibição da germinação dos conídios pelos isolados da levedura. Os resultados de controle in vivo mostraram a viabilidade de S. cerevisiae ACB-K1 e ACB-CR1 para o controle de P. digitatum, em frutos de lima-ácida 'Tahiti' e laranja 'Hamlin', respectivamente; a associação de bicarbonato de sódio com agentes de biocontrole não resultou

  2. Redução de alguns compostos carbonilicos derivados de fenil cetonas empregando-se fermento de pão (Saccharonyces cerevisiae)

    OpenAIRE

    Eugenia Cristina Souza Brenelli

    1994-01-01

    Resumo: Álcoois quirais são intermediários importantes na síntese de substâncias com atividade biológica, a saber, medicamentos, agroquímicos e feromônios. A redução assimétrica de cetonas proquirais por microorganismos, especialmente fermento de pão (Saccharomyces cerevisiae), é uma metodologia que tem se mostrado muito útil na obtenção de álcoois quirais em bons rendimentos químicos e ópticos. Neste trabalho estudou-se a redução assimétrica por fermento de pão de alguns compostos carbonílic...

  3. Metabolic engineering of Saccharomyces cerevisiae for production of butanol isomers.

    Science.gov (United States)

    Generoso, Wesley Cardoso; Schadeweg, Virginia; Oreb, Mislav; Boles, Eckhard

    2015-06-01

    Saccharomyces cerevisiae has decisive advantages in industrial processes due to its tolerance to alcohols and fermentation conditions. Butanol isomers are considered as suitable fuel substitutes and valuable biomass-derived chemical building blocks. Whereas high production was achieved with bacterial systems, metabolic engineering of yeast for butanol production is in the beginning. For isobutanol synthesis, combination of valine biosynthesis and degradation, and complete pathway re-localisation into cytosol or mitochondria gave promising results. However, competing pathways, co-factor imbalances and FeS cluster assembly are still major issues. 1-Butanol production via the Clostridium pathway seems to be limited by cytosolic acetyl-CoA, its central precursor. Endogenous 1-butanol pathways have been discovered via threonine or glycine catabolism. 2-Butanol production was established but was limited by B12-dependence.

  4. Metabolic impact of redox cofactor perturbations in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Hou, Jin; Lages, Nuno; Oldiges, M.

    2009-01-01

    Redox cofactors play a pivotal role in coupling catabolism with anabolism and energy generation during metabolism. There exists a delicate balance in the intracellular level of these cofactors to ascertain an optimal metabolic output. Therefore, cofactors are emerging to be attractive targets...... to induce widespread changes in metabolism. We present a detailed analysis of the impact of perturbations in redox cofactors in the cytosol or mitochondria on glucose and energy metabolism in Saccharomyces cerevisiae to aid metabolic engineering decisions that involve cofactor engineering. We enhanced NADH...... production, while decreasing mitochondrial NADH lowered ethanol production. However, when these reactions were coupled with NADPH production, the metabolic changes were more moderated. The direct consequence of these perturbations could be seen in the shift of the intracellular concentrations...

  5. Bioaccumulation of cadmium by growing Zygosaccharomyces rouxii and Saccharomyces cerevisiae.

    Science.gov (United States)

    Li, Chunsheng; Jiang, Wei; Ma, Ning; Zhu, Yinglian; Dong, Xiaoyan; Wang, Dongfeng; Meng, Xianghong; Xu, Ying

    2014-03-01

    Bioaccumulation via growing cells is a potential technique for heavy metal removal from food materials. The cadmium bioaccumulation characteristics by growing Zygosaccharomyces rouxii and Saccharomyces cerevisiae were investigated. Z. rouxii displayed powerful cadmium removal ability at low cadmium concentrations, which mainly depended on the intracellular cadmium bioaccumulation. The percentage of intracellular cadmium bioaccumulation of both yeasts obviously decreased with the increase of initial biomass and cadmium concentrations. Low pH and elevated concentrations of zinc and copper significantly decreased the intracellular cadmium bioaccumulation of both yeasts but improved the cadmium tolerance and the cell-surface cadmium bioaccumulation of Z. rouxii. Cadmium removal of Z. rouxii was improved by zinc and copper conditionally. Z. rouxii that possessed more powerful cadmium tolerance and removal ability at low pH and high concentration of competing ions can be developed into a potential cadmium removal agent using in complex food environment in future.

  6. Interaction among Saccharomyces cerevisiae pheromone receptors during endocytosis

    Directory of Open Access Journals (Sweden)

    Chien-I Chang

    2014-03-01

    Full Text Available This study investigates endocytosis of Saccharomyces cerevisiae α-factor receptor and the role that receptor oligomerization plays in this process. α-factor receptor contains signal sequences in the cytoplasmic C-terminal domain that are essential for ligand-mediated endocytosis. In an endocytosis complementation assay, we found that oligomeric complexes of the receptor undergo ligand-mediated endocytosis when the α-factor binding site and the endocytosis signal sequences are located in different receptors. Both in vitro and in vivo assays suggested that ligand-induced conformational changes in one Ste2 subunit do not affect neighboring subunits. Therefore, recognition of the endocytosis signal sequence and recognition of the ligand-induced conformational change are likely to be two independent events.

  7. The concentration of ammonia regulates nitrogen metabolism in Saccharomyces cerevisiae.

    Science.gov (United States)

    ter Schure, E G; Silljé, H H; Verkleij, A J; Boonstra, J; Verrips, C T

    1995-11-01

    Saccharomyces cerevisiae was grown in a continuous culture at a single dilution rate with input ammonia concentrations whose effects ranged from nitrogen limitation to nitrogen excess and glucose limitation. The rate of ammonia assimilation (in millimoles per gram of cells per hour) was approximately constant. Increased extracellular ammonia concentrations are correlated with increased intracellular glutamate and glutamine concentrations, increases in levels of NAD-dependent glutamate dehydrogenase activity and its mRNA (gene GDH2), and decreases in levels of NADPH-dependent glutamate dehydrogenase activity and its mRNA (gene GDH1), as well as decreases in the levels of mRNA for the amino acid permease-encoding genes GAP1 and PUT4. The governing factor of nitrogen metabolism might be the concentration of ammonia rather than its flux.

  8. Genetic dissection of acetic acid tolerance in Saccharomyces cerevisiae.

    Science.gov (United States)

    Geng, Peng; Xiao, Yin; Hu, Yun; Sun, Haiye; Xue, Wei; Zhang, Liang; Shi, Gui-Yang

    2016-09-01

    Dissection of the hereditary architecture underlying Saccharomyces cerevisiae tolerance to acetic acid is essential for ethanol fermentation. In this work, a genomics approach was used to dissect hereditary variations in acetic acid tolerance between two phenotypically different strains. A total of 160 segregants derived from these two strains were obtained. Phenotypic analysis indicated that the acetic acid tolerance displayed a normal distribution in these segregants, and suggested that the acetic acid tolerant traits were controlled by multiple quantitative trait loci (QTLs). Thus, 220 SSR markers covering the whole genome were used to detect QTLs of acetic acid tolerant traits. As a result, three QTLs were located on chromosomes 9, 12, and 16, respectively, which explained 38.8-65.9 % of the range of phenotypic variation. Furthermore, twelve genes of the candidates fell into the three QTL regions by integrating the QTL analysis with candidates of acetic acid tolerant genes. These results provided a novel avenue to obtain more robust strains.

  9. Domestication and Divergence of Saccharomyces cerevisiae Beer Yeasts.

    Science.gov (United States)

    Gallone, Brigida; Steensels, Jan; Prahl, Troels; Soriaga, Leah; Saels, Veerle; Herrera-Malaver, Beatriz; Merlevede, Adriaan; Roncoroni, Miguel; Voordeckers, Karin; Miraglia, Loren; Teiling, Clotilde; Steffy, Brian; Taylor, Maryann; Schwartz, Ariel; Richardson, Toby; White, Christopher; Baele, Guy; Maere, Steven; Verstrepen, Kevin J

    2016-09-01

    Whereas domestication of livestock, pets, and crops is well documented, it is still unclear to what extent microbes associated with the production of food have also undergone human selection and where the plethora of industrial strains originates from. Here, we present the genomes and phenomes of 157 industrial Saccharomyces cerevisiae yeasts. Our analyses reveal that today's industrial yeasts can be divided into five sublineages that are genetically and phenotypically separated from wild strains and originate from only a few ancestors through complex patterns of domestication and local divergence. Large-scale phenotyping and genome analysis further show strong industry-specific selection for stress tolerance, sugar utilization, and flavor production, while the sexual cycle and other phenotypes related to survival in nature show decay, particularly in beer yeasts. Together, these results shed light on the origins, evolutionary history, and phenotypic diversity of industrial yeasts and provide a resource for further selection of superior strains. PAPERCLIP.

  10. Tolerance of budding yeast Saccharomyces cerevisiae to ultra high pressure

    Science.gov (United States)

    Shibata, M.; Torigoe, M.; Matsumoto, Y.; Yamamoto, M.; Takizawa, N.; Hada, Y.; Mori, Y.; Takarabe, K.; Ono, F.

    2014-05-01

    Our studies on the tolerance of plants and animals against very high pressure of several GPa have been extended to a smaller sized fungus, the budding yeast Saccharomyces cerevisiae. Several pieces of budding yeast (dry yeast) were sealed in a small teflon capsule with a liquid pressure medium fluorinate, and exposed to 7.5 GPa by using a cubic anvil press. The pressure was kept constant for various duration of time from 2 to 24 h. After the pressure was released, the specimens were brought out from the teflon capsule, and they were cultivated on a potato dextrose agar. It was found that the budding yeast exposed to 7.5 GPa for up to 6 h showed multiplication. However, those exposed to 7.5 GPa for longer than 12 h were found dead. The high pressure tolerance of budding yeast is a little weaker than that of tardigrades.

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

    Directory of Open Access Journals (Sweden)

    Popov Stevan D.

    2005-01-01

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

  12. Preferentially quantized linker DNA lengths in Saccharomyces cerevisiae.

    Science.gov (United States)

    Wang, Ji-Ping; Fondufe-Mittendorf, Yvonne; Xi, Liqun; Tsai, Guei-Feng; Segal, Eran; Widom, Jonathan

    2008-09-12

    The exact lengths of linker DNAs connecting adjacent nucleosomes specify the intrinsic three-dimensional structures of eukaryotic chromatin fibers. Some studies suggest that linker DNA lengths preferentially occur at certain quantized values, differing one from another by integral multiples of the DNA helical repeat, approximately 10 bp; however, studies in the literature are inconsistent. Here, we investigate linker DNA length distributions in the yeast Saccharomyces cerevisiae genome, using two novel methods: a Fourier analysis of genomic dinucleotide periodicities adjacent to experimentally mapped nucleosomes and a duration hidden Markov model applied to experimentally defined dinucleosomes. Both methods reveal that linker DNA lengths in yeast are preferentially periodic at the DNA helical repeat ( approximately 10 bp), obeying the forms 10n+5 bp (integer n). This 10 bp periodicity implies an ordered superhelical intrinsic structure for the average chromatin fiber in yeast.

  13. Preferentially quantized linker DNA lengths in Saccharomyces cerevisiae.

    Directory of Open Access Journals (Sweden)

    Ji-Ping Wang

    Full Text Available The exact lengths of linker DNAs connecting adjacent nucleosomes specify the intrinsic three-dimensional structures of eukaryotic chromatin fibers. Some studies suggest that linker DNA lengths preferentially occur at certain quantized values, differing one from another by integral multiples of the DNA helical repeat, approximately 10 bp; however, studies in the literature are inconsistent. Here, we investigate linker DNA length distributions in the yeast Saccharomyces cerevisiae genome, using two novel methods: a Fourier analysis of genomic dinucleotide periodicities adjacent to experimentally mapped nucleosomes and a duration hidden Markov model applied to experimentally defined dinucleosomes. Both methods reveal that linker DNA lengths in yeast are preferentially periodic at the DNA helical repeat ( approximately 10 bp, obeying the forms 10n+5 bp (integer n. This 10 bp periodicity implies an ordered superhelical intrinsic structure for the average chromatin fiber in yeast.

  14. ACTIVITY OF SUPEROXIDE DISMUTASE ENZYME IN YEAST SACCHAROMYCES CEREVISIAE

    Directory of Open Access Journals (Sweden)

    Blažena Lavová

    2014-02-01

    Full Text Available Reactive oxygen species (ROS with reactive nitrogen species (RNS are known to play dual role in biological systems, they can be harmful or beneficial to living systems. ROS can be important mediators of damage to cell structures, including proteins, lipids and nucleic acids termed as oxidative stress. The antioxidant enzymes protect the organism against the oxidative damage caused by active oxygen forms. The role of superoxide dismutase (SOD is to accelerate the dismutation of the toxic superoxide radical, produced during oxidative energy processes, to hydrogen peroxide and molecular oxygen. In this study, SOD activity of three yeast strains Saccharomyces cerevisiae was determined. It was found that SOD activity was the highest (23.7 U.mg-1 protein in strain 612 after 28 hours of cultivation. The lowest SOD activity from all tested strains was found after 56 hours of cultivation of strain Gyöng (0.7 U.mg-1 protein.

  15. Extreme calorie restriction and energy source starvation in Saccharomyces cerevisiae represent distinct physiological states

    NARCIS (Netherlands)

    Boender, L.G.M.; Almering, M.J.H.; Dijk, M.; Van Maris, A.J.A.; De Winde, J.H.; Pronk, J.T.; Daran-Lapujade, P.

    2011-01-01

    Cultivation methods used to investigate microbial calorie restriction often result in carbon and energy starvation. This study aims to dissect cellular responses to calorie restriction and starvation in Saccharomyces cerevisiae by using retentostat cultivation. In retentostats, cells are continuousl

  16. Systems Biology of Saccharomyces cerevisiae Physiology and its DNA Damage Response

    DEFF Research Database (Denmark)

    Fazio, Alessandro

    damage response (Chapter 5). When DNA damage is repaired, cells restart the cell cycle and resume growth. This process is called damage recovery. In S. cerevisiae, the molecular mechanism of recovery relies on dephosphorylation of Rad53 by protein phosphatases (PPs), that, in case of recovery from MMS......The yeast Saccharomyces cerevisiae is a model organism in biology, being widely used in fundamental research, the first eukaryotic organism to be fully sequenced and the platform for the development of many genomics techniques. Therefore, it is not surprising that S. cerevisiae has also been widely...... used in the field of systems biology during the last decade. This thesis investigates S. cerevisiae growth physiology and DNA damage response by using a systems biology approach. Elucidation of the relationship between growth rate and gene expression is important to understand the mechanisms regulating...

  17. Functional expression of a heterologous nickel-dependent, ATP-independent urease in Saccharomyces cerevisiae

    NARCIS (Netherlands)

    Milne, N.; Luttik, M.A.H.; Cueto Rojas, H.F.; Wahl, A.; Van Maris, A.J.A.; Pronk, J.T.; Daran, J.G.

    2015-01-01

    In microbial processes for production of proteins, biomass and nitrogen-containing commodity chemicals, ATP requirements for nitrogen assimilation affect product yields on the energy producing substrate. In Saccharomyces cerevisiae, a current host for heterologous protein production and potential pl

  18. Dominance of Saccharomyces cerevisiae in alcoholic fermentation processes

    DEFF Research Database (Denmark)

    Albergaria, Helena; Arneborg, Nils

    2016-01-01

    Winemaking, brewing and baking are some of the oldest biotechnological processes. In all of them, alcoholic fermentation is the main biotransformation and Saccharomyces cerevisiae the primary microorganism. Although a wide variety of microbial species may participate in alcoholic fermentation and...

  19. Metabolic engineering of Saccharomyces cerevisiae to improve succinic acid production based on metabolic profiling.

    Science.gov (United States)

    Ito, Yuma; Hirasawa, Takashi; Shimizu, Hiroshi

    2014-01-01

    We performed metabolic engineering on the budding yeast Saccharomyces cerevisiae for enhanced production of succinic acid. Aerobic succinic acid production in S. cerevisiae was achieved by disrupting the SDH1 and SDH2 genes, which encode the catalytic subunits of succinic acid dehydrogenase. Increased succinic acid production was achieved by eliminating the ethanol biosynthesis pathways. Metabolic profiling analysis revealed that succinic acid accumulated intracellularly following disruption of the SDH1 and SDH2 genes, which suggests that enhancing the export of intracellular succinic acid outside of cells increases succinic acid production in S. cerevisiae. The mae1 gene encoding the Schizosaccharomyces pombe malic acid transporter was introduced into S. cerevisiae, and as a result, succinic acid production was successfully improved. Metabolic profiling analysis is useful in producing chemicals for metabolic engineering of microorganisms.

  20. Opportunistic strains of Saccharomyces cerevisiae: a potential risk sold in food products

    Directory of Open Access Journals (Sweden)

    Roberto ePérez-Torrado

    2016-01-01

    Full Text Available In recent decades, fungal infections have emerged as an important health problem associated with more people who present deficiencies in the immune system, such as HIV or transplanted patients. Saccharomyces cerevisiae is one of the emerging fungal pathogens with a unique characteristic: its presence in many food products. S. cerevisiae has an impeccably good food safety record compared to other microorganisms like virus, bacteria and some filamentous fungi. However, humans unknowingly and inadvertently ingest large viable populations of S. cerevisiae (home-brewed beer or dietary supplements that contain yeast. In the last few years, researchers have studied the nature of S. cerevisiae strains and the molecular mechanisms related to infections. Here we review the last advance made in this emerging pathogen and we discuss the implication of using this species in food products.

  1. Removal of Strontium Ions by Immobilized Saccharomyces Cerevisiae in Magnetic Chitosan Microspheres

    Directory of Open Access Journals (Sweden)

    Yanan Yin

    2017-02-01

    Full Text Available A novel biosorbent, immobilized Saccharomyces cerevisiae in magnetic chitosan microspheres was prepared, characterized, and used for the removal of Sr2+ from aqueous solution. The structure and morphology of immobilized S. cerevisiae before and after Sr2+adsorption were observed using scanning electron microscopy with energy dispersive X-ray spectroscopy. The experimental results showed that the Langmuir and Freundlich isotherm models could be used to describe the Sr2+ adsorption onto immobilized S. cerevisiae microspheres. The maximal adsorption capacity (qm was calculated to be 81.96 mg/g by the Langmuir model. Immobilized S. cerevisiae was an effective adsorbent for the Sr2+ removal from aqueous solution.

  2. Stress Tolerance Variations in Saccharomyces cerevisiae Strains from Diverse Ecological Sources and Geographical Locations.

    Directory of Open Access Journals (Sweden)

    Yan-Lin Zheng

    Full Text Available The budding yeast Saccharomyces cerevisiae is a platform organism for bioethanol production from various feedstocks and robust strains are desirable for efficient fermentation because yeast cells inevitably encounter stressors during the process. Recently, diverse S. cerevisiae lineages were identified, which provided novel resources for understanding stress tolerance variations and related shaping factors in the yeast. This study characterized the tolerance of diverse S. cerevisiae strains to the stressors of high ethanol concentrations, temperature shocks, and osmotic stress. The results showed that the isolates from human-associated environments overall presented a higher level of stress tolerance compared with those from forests spared anthropogenic influences. Statistical analyses indicated that the variations of stress tolerance were significantly correlated with both ecological sources and geographical locations of the strains. This study provides guidelines for selection of robust S. cerevisiae strains for bioethanol production from nature.

  3. Copper Tolerance and Biosorption of Saccharomyces cerevisiae during Alcoholic Fermentation.

    Science.gov (United States)

    Sun, Xiang-Yu; Zhao, Yu; 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.

  4. Septins localize to microtubules during nutritional limitation in Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Vázquez de Aldana Carlos R

    2008-10-01

    Full Text Available Abstract Background In Saccharomyces cerevisiae, nutrient limitation stimulates diploid cells to undergo DNA replication and meiosis, followed by the formation of four haploid spores. Septins are a family of proteins that assemble a ring structure at the mother-daughter neck during vegetative growth, where they control cytokinesis. In sporulating cells, the septin ring disassembles and septins relocalize to the prospore membrane. Results Here, we demonstrate that nutrient limitation triggers a change in the localization of at least two vegetative septins (Cdc10 and Cdc11 from the bud neck to the microtubules. The association of Cdc10 and Cdc11 with microtubules persists into meiosis, and they are found associated with the meiotic spindle until the end of meiosis II. In addition, the meiosis-specific septin Spr28 displays similar behavior, suggesting that this is a common feature of septins. Septin association to microtubules is a consequence of the nutrient limitation signal, since it is also observed when haploid cells are incubated in sporulation medium and when haploid or diploid cells are grown in medium containing non-fermentable carbon sources. Moreover, during meiosis II, when the nascent prospore membrane is formed, septins moved from the microtubules to this membrane. Proper organization of the septins on the membrane requires the sporulation-specific septins Spr3 and Spr28. Conclusion Nutrient limitation in S. cerevisiae triggers the sporulation process, but it also induces the disassembly of the septin bud neck ring and relocalization of the septin subunits to the nucleus. Septins remain associated with microtubules during the meiotic divisions and later, during spore morphogenesis, they are detected associated to the nascent prospore membranes surrounding each nuclear lobe. Septin association to microtubules also occurs during growth in non-fermentable carbon sources.

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

    OpenAIRE

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

    2016-01-01

    Background 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, ...

  6. Metabolic Engineering of Ammonium Assimilation in Xylose-Fermenting Saccharomyces cerevisiae Improves Ethanol Production

    OpenAIRE

    Roca, Christophe; Nielsen, Jens; Olsson, Lisbeth

    2003-01-01

    Cofactor imbalance impedes xylose assimilation in Saccharomyces cerevisiae that has been metabolically engineered for xylose utilization. To improve cofactor use, we modified ammonia assimilation in recombinant S. cerevisiae by deleting GDH1, which encodes an NADPH-dependent glutamate dehydrogenase, and by overexpressing either GDH2, which encodes an NADH-dependent glutamate dehydrogenase, or GLT1 and GLN1, which encode the GS-GOGAT complex. Overexpression of GDH2 increased ethanol yield from...

  7. [Expression of inulinase genes in the yeasts Saccharomyces cerevisiae and Kluyveromyces marxianus].

    Science.gov (United States)

    Sokolenko, G G; Karpechenko, N A

    2015-01-01

    Expression of the genes encoding the enzymes involved in inulin, sucrose, and glucose metabolism in the yeasts Saccharomyces cerevisiae and Kluyveromyces marxianus was studied. The exon-intron structure of the relevant genes was identified and the primers for quantitative PCR were optimized. Expression of the genes was found to depend on the carbon source. Glucose was shown to exhibit a repressive effect on inulinase synthesis by K. marxianus, while in S. cerevisiae glucose and sucrose were inulinase inducer and repressor, respectively.

  8. Industrial Systems Biology of Saccharomyces cerevisiae Enables Novel Succinic Acid Cell Factory

    DEFF Research Database (Denmark)

    Otero, José Manuel; Cimini, Donatella; Patil, Kiran Raosaheb

    2013-01-01

    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......-direction of carbon fluxes in S. cerevisiae, and hence show proof of concept that this is a potentially attractive cell factory for over-producing different platform chemicals....

  9. Selection of Indigenous Saccharomyces cerevisiae Strains from Kutjevo Wine Growing Area at the Laboratoy Scale

    OpenAIRE

    Sandi Orlić; Nenad Očić; Ana Jeromel; Katarina Huić; Sulejman Redžepović

    2005-01-01

    The use of selected yeasts for winemaking has clear advantages over traditional spontaneous fermentation. Selection of wine yeasts is usually carried out within the Saccharomyces cerevisiae species. Yeast strains produce different amount of secondary compounds that impart specific characteristics to the wines. This suggests that it is necessary to isolate naturally occuring autochthone strains, which exhibit a metabolic profile that corresponds to each wine. Twenty two strains of S.cerevisiae...

  10. Involvement of heme biosynthesis in control of sterol uptake by Saccharomyces cerevisiae.

    OpenAIRE

    Lewis, T A; Taylor, F R; Parks, L W

    1985-01-01

    Wild-type Saccharomyces cerevisiae do not accumulate exogenous sterols under aerobic conditions, and a mutant allele conferring sterol auxotrophy (erg7) could be isolated only in strains with a heme deficiency. delta-Aminolevulinic acid (ALA) fed to a hem1 (ALA synthetase-) erg7 (2,3-oxidosqualene cyclase-) sterol-auxotrophic strain of S. cerevisiae inhibited sterol uptake, and growth was negatively affected when intracellular sterol was depleted. The inhibition of sterol uptake (and growth o...

  11. Enriquecimento protéico da palma forrageira com Saccharomyces cerevisiae para alimentação de ruminantes Protein enrichment of cactus pear with Saccharomyces cerevisiae for ruminants feeding

    Directory of Open Access Journals (Sweden)

    L.F. Araújo

    2008-04-01

    Full Text Available Avaliou-se o processo de enriquecimento protéico da palma forrageira (Opuntia ficus-indica Mill com levedura Sacharomyces cerevisiae em cultivo semi-sólido, visando melhorar o valor nutritivo da palma para ser utilizada na alimentação de ruminantes. A levedura foi utilizada nas concentrações de 1, 2 e 3% em base úmida no substrato formado pela palma forrageira, incubada em biorreatores durante 6, 12, 24 e 36 horas de fermentação. O delineamento experimental foi inteiramente ao acaso, em arranjo de parcelas subdivididas com quatro repetições. O conteúdo de proteína bruta quando se utilizou concentração de 3% de inóculo, no período de seis horas, aumentou de 4,4% na forma in natura para 10,4% após o processamento. Os teores protéicos na concentração de 1% do inóculo foram de 6,1, 8,1, 8,1 e 9,2%; na concentração de 2%, 9,6, 9,7, 9,8 e 9,8% e na concentração de 3%, 10,4, 10,4 7,9 e 7,9%, nos períodos de 6, 12, 24 e 36 horas de fermentação, respectivamente. Uma fonte alternativa para arraçoamento de ruminantes, pode ser obtida pela bioconversão da palma forrageira.The process of protein enrichment of the forage palm (Opuntia ficus-indica Mill using the Saccharomyces cerevisiae yeast in a semi-solid culture to improve the nutritional value of forage palm for ruminants feeding was evaluated. The yeast concentrations of 1, 2 and 3% (wet basis in the forage palm substrate were used. The periods of incubation were of 6, 12, 24, and 36 hours. A complete randomized experimental design in a split plot arrangement with four replicates was used. The crude protein content increased from 4.4% (in natura to 10.4% when 3% of inoculums were used and the processing period was of 6 hours. The observed protein contents for 1% of the inoculum, used for the fermentation periods of 6, 12, 24, and 36 hours were 6.1, 8.1, 8.1, and 9.2%, respectively. These values were 9.6, 9.7, 9.8, and 9.8% for 2% of the inoculum, and 10.4, 10.4, 7.9, and 7

  12. Efficient Heterologous Transformation of <em>Chlamydomonas> reinhardtiiem> <em>npq2em> Mutant with the Zeaxanthin Epoxidase Gene Isolated and Characterized from<em> Chlorella zofingiensisem>

    Directory of Open Access Journals (Sweden)

    Herminia Rodríguez

    2012-09-01

    Full Text Available In the violaxanthin cycle, the violaxanthin de-epoxidase and zeaxanthin epoxidase catalyze the inter-conversion between violaxanthin and zeaxanthin in both plants and green algae. The zeaxanthin epoxidase gene from the green microalga <em>Chlorella zofingiensisem> (<em>Czzep> has been isolated<em>. em>This gene encodes a polypeptide of 596 amino acids. A single copy of <em>Czzep> has been found in the <em>C. zofingiensisem> genome by Southern blot analysis. qPCR analysis has shown that transcript levels of <em>Czzep> were increased after zeaxanthin formation under high light conditions. The functionality of <em>Czzep> gene by heterologous genetic complementation in the <em>Chlamydomonas> mutant <em>npq2em>, which lacks zeaxanthin epoxidase (ZEP activity and accumulates zeaxanthin in all conditions, was analyzed. The <em>Czzep> gene was adequately inserted in the pSI105 vector and expressed in <em>npq2em>. The positive transformants were able to efficiently convert zeaxanthin into violaxanthin, as well as to restore their maximum quantum efficiency of the PSII (Fv/Fm. These results show that <em>Chlamydomonas> can be an efficient tool for heterologous expression and metabolic engineering for biotechnological applications.

  13. Candida zemplinina can reduce acetic acid produced by Saccharomyces cerevisiae in sweet wine fermentations.

    Science.gov (United States)

    Rantsiou, Kalliopi; Dolci, Paola; Giacosa, Simone; Torchio, Fabrizio; Tofalo, Rosanna; Torriani, Sandra; Suzzi, Giovanna; Rolle, Luca; Cocolin, Luca

    2012-03-01

    In this study we investigated the possibility of using Candida zemplinina, as a partner of Saccharomyces cerevisiae, in mixed fermentations of must with a high sugar content, in order to reduce its acetic acid production. Thirty-five C. zemplinina strains, which were isolated from different geographic regions, were molecularly characterized, and their fermentation performances were determined. Five genetically different strains were selected for mixed fermentations with S. cerevisiae. Two types of inoculation were carried out: coinoculation and sequential inoculation. A balance between the two species was generally observed for the first 6 days, after which the levels of C. zemplinina started to decrease. Relevant differences were observed concerning the consumption of sugars, the ethanol and glycerol content, and acetic acid production, depending on which strain was used and which type of inoculation was performed. Sequential inoculation led to the reduction of about half of the acetic acid content compared to the pure S. cerevisiae fermentation, but the ethanol and glycerol amounts were also low. A coinoculation with selected combinations of S. cerevisiae and C. zemplinina resulted in a decrease of ~0.3 g of acetic acid/liter, while maintaining high ethanol and glycerol levels. This study demonstrates that mixed S. cerevisiae and C. zemplinina fermentation could be applied in sweet wine fermentation to reduce the production of acetic acid, connected to the S. cerevisiae osmotic stress response.

  14. Effect of Saccharomyces cerevisiae strain UFMG A-905 in experimental model of inflammatory bowel disease.

    Science.gov (United States)

    Tiago, F C P; Porto, B A A; Ribeiro, N S; Moreira, L M C; Arantes, R M E; Vieira, A T; Teixeira, M M; Generoso, S V; Nascimento, V N; Martins, F S; Nicoli, J R

    2015-01-01

    In the present study, the protective potential of Saccharomyces cerevisiae strain UFMG A-905 was evaluated in a murine model of acute ulcerative colitis (UC). Six groups of Balb/c mice were used: not treated with yeast and not challenged with dextran sulphate sodium (DSS) (control); treated with S. cerevisiae UFMG A-905 (905); treated with the non-probiotic S. cerevisiae W303 (W303); challenged with DSS (DSS); treated with S. cerevisiae UFMG A-905 and challenged with DSS (905 + DSS); and treated with S. cerevisiae W303 and challenged with DSS (W303 + DSS). Seven days after induction of UC, mice were euthanised to remove colon for enzymatic, immunological, and histopathological analysis. In vivo intestinal permeability was also evaluated. An improvement of clinical manifestations of experimental UC was observed only in mice of the 905 + DSS group when compared to animals from DSS and W303 + DSS groups. This observation was confirmed by histological and morphometrical data and determination of myeloperoxidase and eosinophil peroxidase activities, intestinal permeability and some pro-inflammatory cytokines. S. cerevisiae UFMG A-905 showed to be a potential alternative treatment for UC when used in an experimental animal model of the disease.

  15. Mechanisms of appearance of the Pasteur effect in Saccharomyces cerevisiae: inactivation of sugar transport systems.

    Science.gov (United States)

    Lagunas, R; Dominguez, C; Busturia, A; Sáez, M J

    1982-10-01

    Saccharomyces cerevisiae does not show a noticeable Pasteur effect (activation of sugar catabolism by anaerobiosis) when growing with an excess of sugar and nitrogen source, but it does do so after exhaustion of the nitrogen source in the medium (resting state). We have found that this different behavior of growing and resting S. cerevisiae seems due to differences in the contribution of respiration to catabolism under both states. Growing S. cerevisiae respired only 3 to 20% of the catabolized sugar, depending on the sugar present; the remainder was fermented. In contrast, resting S. cerevisiae respired as much as 25 to 100% of the catabolized sugar. These results suggest that a shift to anaerobiosis would have much greater energetic consequences in resting than in growing S. cerevisiae. In resting S. cerevisiae anaerobiosis would strongly decrease the formation of ATP; as a consequence, various regulatory mechanisms would switch on, producing the observed increase of the rate of glycolysis. The greater significance that respiration reached in resting cells was not due to an increase of the respiratory capacity itself, but to a loss of fermentation which turned respiration into the main catabolic pathway. The main mechanism involved in the loss of fermentation observed during nitrogen starvation was a progressive inactivation of the sugar transport systems that reduced the rate of fermentation to less than 10% of the value observed in growing cells. Inactivation of the sugar transports seems a consequence of the turnover of the sugar carriers whose apparent half-lives were 2 to 7 h.

  16. 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

  17. Dermatoses em renais cronicos em terapia dialitica

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    Luis Alberto Batista Peres

    2014-03-01

    Full Text Available Objetivo: As desordens cutâneas e das mucosas são comuns em pacientes em hemodiálise a longo prazo. A diálise prolonga a expectativa de vida, dando tempo para a manifestação destas anormalidades. Os objetivos deste estudo foram avaliar a prevalência de problemas dermatológicos em pacientes com doença renal crônica (DRC em hemodiálise. Métodos: Cento e quarenta e cinco pacientes com doença renal crônica em hemodiálise foram estudados. Todos os pacientes foram completamente analisados para as alterações cutâneas, de cabelos, mucosas e unhas por um único examinador e foram coletados dados de exames laboratoriais. Os dados foram armazenados em um banco de dados do Microsolft Excel e analisados por estatística descritiva. As variáveis contínuas foram comparadas pelo teste t de Student e as variáveis categóricas utilizando o teste do qui-quadrado ou o teste Exato de Fischer, conforme adequado. Resultados: O estudo incluiu 145 pacientes, com idade média de 53,6 ± 14,7 anos, predominantemente do sexo masculino (64,1% e caucasianos (90,0%. O tempo médio de diálise foi de 43,3 ± 42,3 meses. As principais doenças subjacentes foram: hipertensão arterial em 33,8%, diabetes mellitus em 29,6% e glomerulonefrite crônica em 13,1%. As principais manifestações dermatológicas observadas foram: xerose em 109 (75,2%, equimose em 87 (60,0%, prurido em 78 (53,8% e lentigo em 33 (22,8% pacientes. Conclusão: O nosso estudo mostrou a presença de mais do que uma dermatose por paciente. As alterações cutâneas são frequentes em pacientes em diálise. Mais estudos são necessários para melhor caracterização e manejo destas dermatoses.

  18. Bioassay-Guided Isolation and Identification of Cytotoxic Compounds from <em>Gymnosperma> <em>glutinosum> Leaves

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    Cristina Rodríguez-Padilla

    2012-09-01

    Full Text Available Bioassay-guided fractionation of hexane extracts of<em> Gymnosperma glutinosumem> (Asteraceae leaves, collected in North Mexico, afforded the known compounds hentriacontane (1 and (+-13<em>S>,14<em>R>,15-trihydroxy-<em>ent>-labd-7-ene (2, as well as the new <em>ent>-labdane diterpene (−-13<em>S>,14<em>R>,15-trihydroxy-7-oxo-<em>ent>-labd-8(9-ene (3. In addition, D-glycero-D-galactoheptitol (4 was isolated from the methanolic extract of this plant. Their structures were established on the basis of high-field 1D- and 2D NMR methods supported by HR-MS data. The cytotoxic activity was determined by using the <em>in vitroem> L5178Y-R lymphoma murine model. Hentriacontane (1 and the new <em>ent>-labdane 3 showed weak cytotoxicity, whereas the <em>ent>-labdane 2 showed significant (<em>p> < 0.05 and concentration dependent cytotoxicity (up to 78% against L5178Y-R cells at concentrations ranging from 7.8 to 250 µg/mL.

  19. Improving ethanol fermentation performance of Saccharomyces cerevisiae in very high-gravity fermentation through chemical mutagenesis and meiotic recombination

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jing-Jing; Ding, Wen-Tao; Zhang, Guo-Chang; Wang, Jing-Yu [Tianjin Univ. (China). Dept. of Biochemical Engineering

    2011-08-15

    Genome shuffling is an efficient way to improve complex phenotypes under the control of multiple genes. For the improvement of strain's performance in very high-gravity (VHG) fermentation, we developed a new method of genome shuffling. A diploid ste2/ste2 strain was subjected to EMS (ethyl methanesulfonate) mutagenesis followed by meiotic recombination-mediated genome shuffling. The resulting haploid progenies were intrapopulation sterile and therefore haploid recombinant cells with improved phenotypes were directly selected under selection condition. In VHG fermentation, strain WS1D and WS5D obtained by this approach exhibited remarkably enhanced tolerance to ethanol and osmolarity, increased metabolic rate, and 15.12% and 15.59% increased ethanol yield compared to the starting strain W303D, respectively. These results verified the feasibility of the strain improvement strategy and suggested that it is a powerful and high throughput method for development of Saccharomyces cerevisiae strains with desired phenotypes that is complex and cannot be addressed with rational approaches. (orig.)

  20. em arquitetura e urbanismo

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    Ana Maria Sala Minucci Martins

    2006-01-01

    Full Text Available Está sendo desenvolvido projeto de pesquisa denominado Geometria Fractal e suas Aplicações em Arquitetura e Urbanismo, com o fito de estudar e desenvolver ferramentas analíticas e propositivas para serem aplicadas em arquitetura e urbanismo, com base em conceitos provenientes da geometria fractal.

  1. Antimicrobial Activity of Geranium Oil against Clinical Strains<em> em>of <em>Staphylococcus aureusem>

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    Monika Sienkiewicz

    2012-08-01

    Full Text Available The aim of this work was to investigate the antibacterial properties of geranium oil obtained from <em>Pelargonium graveolensem> Ait. (family <em>Geraniaceae>, against one standard <em>S. aureus em>strain ATCC 433000 and seventy clinical <em>S. aureusem> strains. The agar dilution method was used for assessment of bacterial growth inhibition at various concentrations of geranium oil. Susceptibility testing of the clinical strains to antibiotics was carried out using the disk-diffusion and E-test methods. The results of our experiment showed that the oil from <em>P. graveolensem> has strong activity against all of the clinical <em>S. aureusem> isolates—including multidrug resistant strains, MRSA strains and MLSB-positive strains—exhibiting MIC values of 0.25–2.50 μL/mL.

  2. The Interaction between Saccharomyces cerevisiae and Non-Saccharomyces Yeast during Alcoholic Fermentation Is Species and Strain Specific.

    Science.gov (United States)

    Wang, Chunxiao; Mas, Albert; Esteve-Zarzoso, Braulio

    2016-01-01

    The present study analyzes the lack of culturability of different non-Saccharomyces strains due to interaction with Saccharomyces cerevisiae during alcoholic fermentation. Interaction was followed in mixed fermentations with 1:1 inoculation of S. cerevisiae and ten non-Saccharomyces strains. Starmerella bacillaris, and Torulaspora delbrueckii indicated longer coexistence in mixed fermentations compared with Hanseniaspora uvarum and Metschnikowia pulcherrima. Strain differences in culturability and nutrient consumption (glucose, alanine, ammonium, arginine, or glutamine) were found within each species in mixed fermentation with S. cerevisiae. The interaction was further analyzed using cell-free supernatant from S. cerevisiae and synthetic media mimicking both single fermentations with S. cerevisiae and using mixed fermentations with the corresponding non-Saccharomyces species. Cell-free S. cerevisiae supernatants induced faster culturability loss than synthetic media corresponding to the same fermentation stage. This demonstrated that some metabolites produced by S. cerevisiae played the main role in the decreased culturability of the other non-Saccharomyces yeasts. However, changes in the concentrations of main metabolites had also an effect. Culturability differences were observed among species and strains in culture assays and thus showed distinct tolerance to S. cerevisiae metabolites and fermentation environment. Viability kit and recovery analyses on non-culturable cells verified the existence of viable but not-culturable status. These findings are discussed in the context of interaction between non-Saccharomyces and S. cerevisiae.

  3. The Interaction between Saccharomyces cerevisiae and Non-Saccharomyces Yeast during Alcoholic Fermentation is Species and Strain Specific

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    Chunxiao eWang

    2016-04-01

    Full Text Available The present study analyzes the lack of culturability of different non-Saccharomyces strains due to interaction with Saccharomyces cerevisiae during alcoholic fermentation. Interaction was followed in mixed fermentations with 1:1 inoculation of S. cerevisiae and ten non-Saccharomyces strains. Starmerella bacillaris and Torulaspora delbrueckii indicated longer coexistence in mixed fermentations compared with Hanseniaspora uvarum and Metschnikowia pulcherrima. Strain differences in culturability and nutrient consumption (glucose, alanine, ammonium, arginine or glutamine were found within each species in mixed fermentation with S. cerevisiae. The interaction was further analyzed using cell-free supernatant from S. cerevisiae and synthetic media mimicking both single fermentations with S. cerevisiae and using mixed fermentations with the corresponding non-Saccharomyces species. Cell-free S. cerevisiae supernatants induced faster culturability loss than synthetic media corresponding to the same fermentation stage. This demonstrated that some metabolites produced by S. cerevisiae played the main role in the decreased culturability of the other non-Saccharomyces yeasts. However, changes in the concentrations of main metabolites had also an effect. Culturability differences were observed among species and strains in culture assays and thus showed distinct tolerance to S. cerevisiae metabolites and fermentation environment. Viability kit and recovery analyses on non-culturable cells verified the existence of viable but not-culturable status. These findings are discussed in the context of interaction between non-Saccharomyces and S. cerevisiae.

  4. AÇÃO ANTILISTERIAL DO EXTRATO BRUTO DE Bacillus Amyloliquefaciens EM DIFERENTES CONCENTRAÇÕES DE PROTEÍNA, pH E SAL

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    M. A. PEREIRA

    2008-09-01

    Full Text Available

    O elevado índice de morbidade em função da contaminação dos alimentos tem aumentado a necessidade de metodologias alternativas para conservação dos mesmos. Nesse sentido, essa pesquisa teve por objetivo: (1 otimizar a ação antilisterial do extrato bruto produzido por Bacillus amyloliquefaciens em diferentes concentrações proteicas, pH e sal; (2 avaliar a ação do extrato bruto otimizado em ostras artificialmente contaminadas com Listeria monocytogenes. A ação do extrato bruto em diferentes concentrações de proteína (0,0; 5,0; 40; 80 µg/mL sobre o inóculo de 106 UFC.mL-1 de Listeria monocytogenes foi verificada em caldo TSB-YE previamente ajustado para pH 4,0 e 8,0 e concentrações de NaCl de 0; 2,5 e 4,5 % p/v. Os ensaios foram realizados à temperatura de 25ºC em estufa DBO. Para determinar a recuperação microbiana, realizaram-se contagens de Listeria monocytogenes a cada 4 h, por até 50 h. Dos tratamentos testados, a combinação de 80 g/mL de proteína do extrato bruto, pH 4,0 e 4,5 % de NaCl mostrou melhor performance quanto a atividade antimicrobiana, chegando a uma redução de até 5 ciclos logarítmicos de Listeria monocytogenes. Quando testada a ação do tratamento conjunto de 80 g/mL de extrato bruto, pH 4,0 e 4,5 % de NaCl sobre carne de ostra, obteve-se uma redução no número de Listeria monocytogenes de aproximadamente 3 ciclos logarítmicos, (3,0x106 para 1,5x103 UFC.mL-1, após 24 h de incubação a 25ºC. Esses resultados indicam a possível utilização do antimicrobiano produzido por Bacillus amyloliquefaciens como conservador de alimentos.

  5. Accumulation and chemical states of radiocesium by fungus Saccharomyces cerevisiae

    Science.gov (United States)

    Ohnuki, Toshihiko; Sakamoto, Fuminori; Kozai, Naofumi; Yamasaki, Shinya; Yu, Qianqian

    2014-05-01

    After accident of Fukushima Daiichi Nuclear Power Plant, the fall-out radiocesium was deposited on the ground. Filamentous fungus is known to accumulate radiocesium in environment, even though many minerals are involved in soil. These facts suggest that fungus affect the migration behavior of radiocesium in the environment. However, accumulation mechanism of radiocesium by fungus is not understood. In the present study, accumulation and chemical states change of Cs by unicellular fungus of Saccharomyces cerevisiae have been studied to elucidate the role of microorganisms in the migration of radiocesium in the environment. Two different experimental conditions were employed; one is the accumulation experiments of radiocesium by S. cerevisiae from the agar medium containing 137Cs and a mineral of zeolite, vermiculite, smectite, mica, or illite. The other is the experiments using stable cesium to examine the chemical states change of Cs. In the former experiment, the cells were grown on membrane filter of 0.45 μm installed on the agar medium. After the grown cells were weighed, radioactivity in the cells was measured by an autoradiography technique. The mineral weight contents were changed from 0.1% to 1% of the medium. In the latter experiment, the cells were grown in the medium containing stable Cs between 1 mM and 10mM. The Cs accumulated cells were analyzed by SEM-EDS and EXAFS. The adsorption experiments of cesium by the cells under resting condition were also conducted to test the effect of cells metabolic activity. Without mineral in the medium, cells of S. cerevisiae accumulated 1.5x103 Bq/g from the medium containing 137Cs of 2.6x102 Bq/g. When mineral was added in the medium, concentration of 137Cs in the cells decreased. The concentration of 137Cs in the cells from the medium containing different minerals were in the following order; smectite, illite, mica > vermiculite > zeolite. This order was nearly the same as the inverse of distribution coefficient of

  6. EM International. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    1993-07-01

    It is the intent of EM International to describe the Office of Environmental Restoration and Waste Management`s (EM`s) various roles and responsibilities within the international community. Cooperative agreements and programs, descriptions of projects and technologies, and synopses of visits to international sites are all highlighted in this semiannual journal. Focus on EM programs in this issue is on international collaboration in vitrification projects. Technology highlights covers: in situ sealing for contaminated sites; and remote sensors for toxic pollutants. Section on profiles of countries includes: Arctic contamination by the former Soviet Union, and EM activities with Germany--cooperative arrangements.

  7. Prevalence reduction of pathogens in poultry fed with Saccharomyces cerevisiae

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    Fanelli, A.

    2015-01-01

    Full Text Available Description of the subject. The growth of new antibiotic-resistant strains of pathogens represents a huge problem in poultry rearing. There is evidence that dietary yeast could be effective in the protection against a variety of pathogens that can affect poultry health and cause foodborne diseases in humans. Since still few or contradictory information are available for this topic. Objectives. The objective of this study was to investigate the effects of live yeast supplementation in broiler chickens on Salmonella enteritidis and Campylobacter jejuni content in feces, cecum, and skin. Method. Supplemented yeast consisted of Saccharomyces cerevisiae (Levucell® SB20, type boulardii I-1079, Lallemand, France and was administered at a rate of 1 x 106 CFU·g-1 of feed. On day ten of life, birds were orally challenged with S. enteritidis (1 x 105 CFU/bird and C. jejuni (3 x 105 CFU/bird. Growth performance, and coliforms, yeasts and lactobacilli enumeration were evaluated on day 0, 10, 20 and 38. Ten and eighteen days post infection (PI, 10 animals per replicate were slaughtered and pooled ceca content were analyzed for yeast enumeration and Salmonella and Campylobacter frequency and enumeration. The presence and the enumeration of Salmonella and Campylobacter in neck and breast skin were performed on one subject per replicate. Results. Dietary S. cerevisiae increased yeast and lactobacilli (p = 0.01 count, while Salmonella enumeration and frequency significantly decreased in neck (p = 0.03 and tended to decrease in cecum (p = 0.06, feces (p = 0.06, and breast (p = 0.08. On 10d PI Campylobacter presence was decreased in cecum (p = 0.01, feces (p < 0.01, breast skin (p = 0.04 and neck skin (p < 0.01, while the enumeration was found to be lower in feces (p < 0.01 and neck skin (p = 0.05. At the end of the trial the frequency of this pathogen was decreased in feces (p < 0.01, and breast skin (p = 0.02, while the enumeration was diminished in cecum (p

  8. Rapid and efficient galactose fermentation by engineered Saccharomyces cerevisiae.

    Science.gov (United States)

    Quarterman, Josh; Skerker, Jeffrey M; Feng, Xueyang; Liu, Ian Y; Zhao, Huimin; Arkin, Adam P; Jin, Yong-Su

    2016-07-10

    In the important industrial yeast Saccharomyces cerevisiae, galactose metabolism requires energy production by respiration; therefore, this yeast cannot metabolize galactose under strict anaerobic conditions. While the respiratory dependence of galactose metabolism provides benefits in terms of cell growth and population stability, it is not advantageous for producing fuels and chemicals since a substantial fraction of consumed galactose is converted to carbon dioxide. In order to force S. cerevisiae to use galactose without respiration, a subunit (COX9) of a respiratory enzyme was deleted, but the resulting deletion mutant (Δcox9) was impaired in terms of galactose assimilation. Interestingly, after serial sub-cultures on galactose, the mutant evolved rapidly and was able to use galactose via fermentation only. The evolved strain (JQ-G1) produced ethanol from galactose with a 94% increase in yield and 6.9-fold improvement in specific productivity as compared to the wild-type strain. (13)C-metabolic flux analysis demonstrated a three-fold reduction in carbon flux through the TCA cycle of the evolved mutant with redirection of flux toward the fermentation pathway. Genome sequencing of the JQ-G1 strain revealed a loss of function mutation in a master negative regulator of the Leloir pathway (Gal80p). The mutation (Glu348*) in Gal80p was found to act synergistically with deletion of COX9 for efficient galactose fermentation, and thus the double deletion mutant Δcox9Δgal80 produced ethanol 2.4 times faster and with 35% higher yield than a single knockout mutant with deletion of GAL80 alone. When we introduced a functional COX9 cassette back into the JQ-G1 strain, the JQ-G1-COX9 strain showed a 33% reduction in specific galactose uptake rate and a 49% reduction in specific ethanol production rate as compared to JQ-G1. The wild-type strain was also subjected to serial sub-cultures on galactose but we failed to isolate a mutant capable of utilizing galactose without

  9. Ethanol fermentation in an immobilized cell reactor using Saccharomyces cerevisiae.

    Science.gov (United States)

    Najafpour, Ghasem; Younesi, Habibollah; Syahidah Ku Ismail, Ku

    2004-05-01

    Fermentation of sugar by Saccharomyces cerevisiae, for production of ethanol in an immobilized cell reactor (ICR) was successfully carried out to improve the performance of the fermentation process. The fermentation set-up was comprised of a column packed with beads of immobilized cells. The immobilization of S. cerevisiae was simply performed by the enriched cells cultured media harvested at exponential growth phase. The fixed cell loaded ICR was carried out at initial stage of operation and the cell was entrapped by calcium alginate. The production of ethanol was steady after 24 h of operation. The concentration of ethanol was affected by the media flow rates and residence time distribution from 2 to 7 h. In addition, batch fermentation was carried out with 50 g/l glucose concentration. Subsequently, the ethanol productions and the reactor productivities of batch fermentation and immobilized cells were compared. In batch fermentation, sugar consumption and ethanol production obtained were 99.6% and 12.5% v/v after 27 h while in the ICR, 88.2% and 16.7% v/v were obtained with 6 h retention time. Nearly 5% ethanol production was achieved with high glucose concentration (150 g/l) at 6 h retention time. A yield of 38% was obtained with 150 g/l glucose. The yield was improved approximately 27% on ICR and a 24 h fermentation time was reduced to 7 h. The cell growth rate was based on the Monod rate equation. The kinetic constants (K(s) and mu(m)) of batch fermentation were 2.3 g/l and 0.35 g/lh, respectively. The maximum yield of biomass on substrate (Y(X-S)) and the maximum yield of product on substrate (Y(P-S)) in batch fermentations were 50.8% and 31.2% respectively. Productivity of the ICR were 1.3, 2.3, and 2.8 g/lh for 25, 35, 50 g/l of glucose concentration, respectively. The productivity of ethanol in batch fermentation with 50 g/l glucose was calculated as 0.29 g/lh. Maximum production of ethanol in ICR when compared to batch reactor has shown to increase

  10. Esporos de Clostridium botulinum em mel comercializado no Estado de São Paulo e em outros Estados brasileiros Clostridium botulinum spores in honey commercialized in São Paulo and other Brazilian states

    Directory of Open Access Journals (Sweden)

    Adriana Valim Ferreira Ragazani

    2008-04-01

    Full Text Available O botulismo infantil tem afetado crianças abaixo de um ano de idade em várias regiões do mundo, e o mel tem sido identificado como uma das mais importantes fontes de intoxicação alimentar. Apesar disso, há dados escassos sobre o botulismo entre crianças no Brasil, especialmente no tipo de alimento comercial mais implicado nesta patologia. Este estudo pretendeu investigar a presença de esporos de Clostridium botulinum em mel comercializado no Brasil. Cem amostras de mel comercializado em seis diferentes Estados brasileiros (SP, MG, GO, CE, MT, SC foram pesquisados para a presença de esporos de Clostridium botulinum, usando o choque térmico, seguido pela inoculação em caldo Cooked Meat Medium (Difco® e incubado em condições anaeróbias. As culturas positivas foram analisadas através de esfregaços corados pelo Gram e semeadas em placas de Reinforced Clostrideo Agar (Difco® e placas de Sulfito Polimixina Sulfadiazina -SPS (Difco®, as quais foram incubadas em condições anaeróbicas para obter colônias desta bactéria. As colônias positivas foram submetidas a teste de toxicidade através da inoculação em camundongos susceptíveis e caracterização bioquímica. Foram encontradas colônias de Clostridium botulinum que produzem toxinas ativas em 7% das amostras de mel comercial, realçando a relevância deste microrganismo para a saúde pública devido ao alto risco potencial de o mel comercializado nestas regiões brasileiras causar o botulismo infantil, especialmente em crianças abaixo de um ano de idade.Infant botulism has been affecting children under one year of age in several regions of the world and honey has been identified as one of the most important source of this food borne disease. Despite this, there are scarce data about botulism among children in Brazil, specially the type commercial food most implicated in this pathology. This study aimed at investigating the presence of spores of Clostridium botulinum in honey

  11. Microsatellite Loci in the Gypsophyte <em>Lepidium subulatum em>(Brassicaceae, and Transferability to Other <em>Lepidieae>

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    José Gabriel Segarra-Moragues

    2012-09-01

    Full Text Available Polymorphic microsatellite markers were developed for the Ibero-North African, strict gypsophyte <em>Lepidium subulatumem> to unravel the effects of habitat fragmentation in levels of genetic diversity, genetic structure and gene flow among its populations. Using 454 pyrosequencing 12 microsatellite loci including di- and tri-nucleotide repeats were characterized in <em>L. subulatumem>. They amplified a total of 80 alleles (2–12 alleles per locus in a sample of 35 individuals of <em>L. subulatumem>, showing relatively high levels of genetic diversity, <em>H>O = 0.645, <em>H>E = 0.627. Cross-species transferability of all 12 loci was successful for the Iberian endemics <em>Lepidium cardaminesem>, <em>Lepidium stylatumem>, and the widespread, <em>Lepidium graminifoliumem> and one species each of two related genera, <em>Cardaria drabaem> and <em>Coronopus didymusem>. These microsatellite primers will be useful to investigate genetic diversity, population structure and to address conservation genetics in species of <em>Lepidium>.

  12. Aderência in vitro do Staphylococcus epidermidis e da Pseudomonas alcaligenes em lentes intra-oculares In vitro adherence of Staphylococcus epidermidis and Pseudomonas alcaligenes to intraocular lenses

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    Patrícia Ioschpe Gus

    2006-06-01

    Full Text Available OBJETIVO: Quantificar e comparar a aderência in vitro das bactérias Staphylococcus epidermidis e Pseudomonas alcaligenes em diferentes tipos de lentes intra-oculares (LIOs. MÉTODOS: Quatorze lentes intra-oculares foram usadas no experimento. Quatro de polimetilmetacrilato (PMMA, quatro de silicone, quatro de hidrogel e duas de acrílico. Oito lentes intra-oculares foram colocadas em oito tubos de ensaio contendo 4 ml de suspensão de Pseudomonas alcaligenes, e seis lentes intra-oculares foram colocadas em seis tubos de ensaio contendo 4 ml de suspensão de Staphylococcus epidermidis. A concentração do caldo utilizada para o teste de aderência foi de 10(8 unidades formadoras de colônias por mililitro (CFU/mL que corresponde a 0,5 na escala de McFarland. As lentes foram incubadas a 37° por duas horas. Após, foram removidas dos caldos e enxaguadas em água destilada estéril por duas vezes. As lentes foram cultivadas em placas de ágar-sangue a 35-37° e evaliadas a cada 24h por um período de 72h. Nas amostras que tiveram crescimento bacteriano, foram contadas as colônias utilizando os métodos convencionais de laboratório. Todos os ensaios foram executados em duplicata. RESULTADOS: A aderência do Staphylococcus epidermidis nas lentes de PMMA foi menor se comparada com as de silicone e de hidrogel. A aderência daPseudomonas alcaligenes nas lentes de hidrogel foi menor se comparada com as de silicone, PMMA e acrílico. CONCLUSÃO: Os resultados sugerem que a aderência do Staphylococcus epidermidis e da Pseudomonas alcaligenes nas lentes intra-oculares é influenciada pelo tipo de material da lente e pela espécie do microorganismo. A aderência bacteriana pode ter papel importante na patogenicidade da endoftalmite pós-cirurgia de catarata.PURPOSE: To quantify and compare the in vitro adherence of Staphylococcus epidermidis and Pseudomonas alcaligenes to different intraocular lenses (IOLs. METHODS: Fourteen intraocular lenses were

  13. Crescimento bacteriano em perfluorocarbonos líquidos: estudo "in vitro" Bacterial growth in perfluorocarbon liquids: an in vitro study

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    Leciana Rorato Chiconelli Vanzo

    2001-02-01

    Full Text Available Objetivo: Verificar o crescimento de P. aeruginosa e S. aureus em perfluoroctano líquido . Métodos: Foram utilizados três meios de cultura: perfluoroctano, caldo de digestão de soja mais caseína e solução salina a 0,9%. Dividiram-se 5 ml de perfluoroctano em frascos contendo 1 ml cada. Nos frascos 1 e 2 inoculou-se 1 colônia inteira de P. aeruginosa e nos recipientes 3 e 4 a mesma quantidade de S. aureus. O frasco 5 serviu como controle sem sofrer contaminação. Inoculou-se também 1 colônia de cada bactéria em 1 ml dos demais meios de cultura. Colônias inteiras foram utilizadas pois o perfluoroctano é imiscível em água. As soluções foram mantidas em incubador a 37ºC por 10 dias. Em câmara de fluxo laminar foi realizado o repique utilizando-se alça calibrada 1:1000 no tempo zero, 72 h, 168 h e 240 h após a contaminação. O crescimento bacteriano foi verificado por meio da contagem de colônias em placas de agar sangue 24 h após cada repique. Resultados: Houve crescimento de P. aeruginosa e S. aureus no tempo zero em todos os meios, confirmando a inoculação bacteriana. Nas horas seguintes o crescimento não mais foi observado em perfluoroctano. Ambas as bactérias desenvolveram-se abundantemente nos demais meios de cultura em todos os tempos. No frasco controle não houve crescimento bacteriano. Conclusão: Os resultados deste estudo "in vitro" demonstraram que o perfluoroctano parece não representar um meio favorável para o crescimento bacteriano.Purpose: To determine the growth of P. aeruginosa and S. aureus in liquid perfluoroctane perfluoroctane. Methods: Three culture media were used: perfluoroctane, soy and casein digestion broth and 0.9% saline. Five ml perfluoroctane were distributed among 1 ml flasks. Flasks 1 and 2 were inoculated with 1 entire colony of P. aeruginosa and flasks 3 and 4 were inoculated with the same amount of S. aureus. Flask 5 served as control without any contamination. One colony of each

  14. New Trifluoromethyl Triazolopyrimidines as Anti-<em>Plasmodium> <em>falciparum> Agents

    Directory of Open Access Journals (Sweden)

    Núbia Boechat

    2012-07-01

    Full Text Available According to the World Health Organization, half of the World’s population, approximately 3.3 billion people, is at risk for developing malaria. Nearly 700,000 deaths each year are associated with the disease. Control of the disease in humans still relies on chemotherapy. Drug resistance is a limiting factor, and the search for new drugs is important. We have designed and synthesized new 2-(trifluoromethyl[1,2,4]triazolo[1,5-<em>a>]pyrimidine derivatives based on bioisosteric replacement of functional groups on the anti-malarial compounds mefloquine and amodiaquine. This approach enabled us to investigate the impact of: (i ring bioisosteric replacement; (ii a CF3 group substituted at the 2-position of the [1,2,4]triazolo[1,5-<em>a>]pyrimidine scaffold and (iii a range of amines as substituents at the 7-position of the of heterocyclic ring; on <em>in vitroem> activity against <em>Plasmodium falciparumem>. According to docking simulations, the synthesized compounds are able to interact with <em>P. falciparumem> dihydroorotate dehydrogenase (<em>Pf>DHODH through strong hydrogen bonds. The presence of a trifluoromethyl group at the 2-position of the [1,2,4]triazolo[1,5-<em>a>]pyrimidine ring led to increased drug activity. Thirteen compounds were found to be active, with IC50 values ranging from 0.023 to 20 µM in the anti-HRP2 and hypoxanthine assays. The selectivity index (SI of the most active derivatives 5, 8, 11 and 16 was found to vary from 1,003 to 18,478.

  15. Screening and Analysis of the Potential Bioactive Components in Rabbit Plasma after Oral Administration of Hot-Water Extracts from Leaves of <em>B>ambusa em>>textilis em>McClure

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    Jia Sun

    2012-07-01

    Full Text Available <em>Bambusa textilisem> McClure is a traditional Chinese medicinal plant belonging to the Bambusoideae subfamily and used to treat chronic fever and infectious diseases. To investigate the bioactive compounds absorbed in the rabbit blood after oral administration of hot-<em>water extractem>>s from em>>the leaves of em>>B. textilisem> McClure, a validated chromatographic fingerprint method was established using LC-Q-TOF-MS. Twenty compounds in bamboo leaves and three potential bioactive compounds in rabbit plasma were detected. Of the twenty detected compounds <em>in vitroem>, fifteen of which were tentatively identified either by comparing the retention time and mass spectrometry data with that of reference compounds or by reviewing the literature. Three potential bioactive compounds, including (<em>E-p>-coumaric acid, (<em>Z-p>-coumaric acid, and apigenin-8-<em>C>-β-D-(2"-<em>O>-α-L-rhamnosyl-gluco-pyranoside, were detected in both <em>the leaves of em>>B. textilis em>McClure and rabbit plasma. Of the three compounds, apigenin-8-<em>C>-β-D-(2"-<em>O>-α-L-rhamnosylglucopyranoside was identified based on its UV, MS, and NMR spectra. This study provides helpful chemical information for further pharmacology and active mechanism research on <em>B. textilisem> McClure.

  16. Genotoxicity assessment of amaranth and allura red using Saccharomyces cerevisiae.

    Science.gov (United States)

    Jabeen, Hafiza Sumara; ur Rahman, Sajjad; Mahmood, Shahid; Anwer, Sadaf

    2013-01-01

    Amaranth (E123) and Allura red (E129), very important food azo dyes used in food, drug, paper, cosmetic and textile industries, were assessed for their genotoxic potential through comet assay in yeast cells. Comet assay was standardized by with different concentration of H(2)O(2). Concentrations of Amaranth and Allura red were maintained in sorbitol buffer starting from 9.76 to 5,000 μg/mL and 1 × 10(4) cells were incubated at two different incubation temperatures 28 and 37°C. Amaranth (E123) and Allura red (E129) were found to exhibit their genotoxic effect directly in Saccharomyces cerevisiae. No significant genotoxic activity was observed for Amaranth and Allura red at 28°C but at 37°C direct relation of Amaranth concentration with comet tail was significant and no positive relation was seen with time exposure factor. At 37°C the minimum concentration of Amaranth and Allura red at which significant DNA damage observed through comet assay was 1,250 μg/mL in 2nd h post exposure time. The results indicated that food colors should be carefully used in baking products as heavy concentration of food colors could affect the fermentation process of baking.

  17. Protein disorder reduced in Saccharomyces cerevisiae to survive heat shock

    Science.gov (United States)

    Vicedo, Esmeralda; Gasik, Zofia; Dong, Yu-An; Goldberg, Tatyana; Rost, Burkhard

    2015-01-01

    Recent experiments established that a culture of Saccharomyces cerevisiae (baker’s yeast) survives sudden high temperatures by specifically duplicating the entire chromosome III and two chromosomal fragments (from IV and XII). Heat shock proteins (HSPs) are not significantly over-abundant in the duplication. In contrast, we suggest a simple algorithm to “ postdict ” the experimental results: Find a small enough chromosome with minimal protein disorder and duplicate this region. This algorithm largely explains all observed duplications. In particular, all regions duplicated in the experiment reduced the overall content of protein disorder. The differential analysis of the functional makeup of the duplication remained inconclusive. Gene Ontology (GO) enrichment suggested over-representation in processes related to reproduction and nutrient uptake. Analyzing the protein-protein interaction network (PPI) revealed that few network-central proteins were duplicated. The predictive hypothesis hinges upon the concept of reducing proteins with long regions of disorder in order to become less sensitive to heat shock attack. PMID:26673203

  18. Saccharomyces cerevisiae Fermentation Effects on Pollen: Archaeological Implications

    Directory of Open Access Journals (Sweden)

    Crystal A. Dozier

    2016-03-01

    Full Text Available Pollen is the reproductive agent of flowering plants; palynology is utilized by archaeologists because sporopollenin, a major component in the exine of pollen grains, is resistant to decay and morphologically distinctive. Wine, beer, and mead have been identified in the archaeological record by palynological assessment due to indicator species or due to a pollen profile similar to that recovered from honey, a common source of sugar in a variety of fermented beverages. While most palynologists have assumed that pollen grains are resistant to alcoholic fermentation, a recent study in food science implies that pollen is a yeast nutrient because pollen-enriched meads produce more alcohol. The experiment presented here explores the potential distortion of the pollen record through fermentation by brewing a traditional, pollen-rich mead with Saccharomyces cerevisiae. In this experiment, the pollen grains did not undergo any discernible morphological changes nor were distorted in the pollen profile. Any nutrition that the yeast garners from the pollen therefore leaves sporopollenin intact. These results support palynological research on residues of alcoholic beverages and confirms that the fermentation process does not distort the pollen profile of the original substance. The paper concludes with the potential and limits of palynological study to assess fermentation within the archaeological record.

  19. Oxygen requirements of yeasts. [Saccharomyces cerevisiae; Candida tropicalis

    Energy Technology Data Exchange (ETDEWEB)

    Visser, W.; Scheffers, W.A.; Batenburg-Van Der Vegte, W.H.; Van Dijken, J.P. (Delft Univ. of Technology (Netherlands))

    1990-12-01

    Type species of 75 yeast genera were examined for their ability to grow anaerobically in complex and mineral media. To define anaerobic conditions, we added a redox indicator, resazurin, to the media to determine low redox potentials. All strains tested were capable of fermenting glucose to ethanol in oxygen-limited shake-flask cultures, even those of species generally regarded as nonfermentative. However, only 23% of the yeast species tested grew under anaerobic conditions. A comparative study with a number of selected strains revealed that Saccharomyces cerevisiae stands out as a yeast capable of rapid growth at low redox potentials. Other yeasts, such as Torulaspora delbrueckii and Candida tropicalis, grew poorly ({mu}{sub max}, 0.03 and 0.05 h{sup {minus}1}, respectively) under anaerobic conditions in mineral medium supplemented with Tween 80 and ergosterol. The latter organisms grew rapidly under oxygen limitation and then displayed a high rate of alcoholic fermentation. It can be concluded that these yeasts have hitherto-unidentified oxygen requirements for growth.

  20. Biotransformation of malachite green by Saccharomyces cerevisiae MTCC 463.

    Science.gov (United States)

    Jadhav, J P; Govindwar, S P

    2006-03-01

    In recent years, use of microbial biomass for decolourization of textile industry wastewater is becoming a promising alternative in which some bacteria and fungi are used to replace present treatment processes. Saccharomyces cerevisiae MTCC 463 decolourized the triphenylmethane dyes (malachite green, cotton blue, methyl violet and crystal violet) by biosorption, showing different decolourization patterns. However, malachite green decolourized by biosorption at the initial stage and further biodegradation occurred, about 85% in plain distilled water within 7 h, and about 95.5% in 5% glucose medium within 4 h, under aerobic conditions and at room temperature. Decolourization of malachite green depends on various conditions, such as concentration of dye, concentration of cells, composition of medium and agitation. HPLC, UV-VIS, FTIR and TLC analysis of samples extracted with ethyl acetate from decolourized culture flasks confirmed the biodegradation of malachite green into several metabolites. A study of the enzymes responsible for the biodegradation of malachite green in the control and cells obtained after decolourization showed the activities of laccase, lignin peroxidase, NADH-DCIP reductase, malachite green reductase and aminopyrine N-demethylase in control cells. A significant increase in the activities of NADH-DCIP reductase and MG reductase was observed in the cells obtained after decolourization, indicating a major involvement of reductases in malachite green degradation.

  1. Localization of nuclear retained mRNAs in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Thomsen, Rune; Libri, Domenico; Boulay, Jocelyne

    2003-01-01

    in the rat7–1 strain colocalize predominantly with nucleolar antigens. Bulk poly(A)+ RNA, on the other hand, is localized primarily to the nuclear rim. Interestingly, the RNA binding nucleocytoplasmic shuttle protein Npl3p shows strong colocalization with bulk poly(A)+ RNA, regardless of its nuclear location...... in retaining RNAs in these foci; on deletion of the exosome component Rrp6p, the RNA is released. To determine the exact nuclear location of retained as well as released mRNAs, we have used mRNA export mutant strains to analyze the spatial relationship between newly synthesized heat shock mRNA, the chromosomal...... site of transcription, and known S. cerevisiae nuclear structures such as the nucleolus and the nucleolar body. Our results show that retained SSA4 RNA localizes to an area in close proximity to the SSA4 locus. On deletion of Rrp6p and release from the genomic locus, heat shock mRNAs produced...

  2. YPA: an integrated repository of promoter features in Saccharomyces cerevisiae.

    Science.gov (United States)

    Chang, Darby Tien-Hao; Huang, Cheng-Yi; Wu, Chi-Yeh; Wu, Wei-Sheng

    2011-01-01

    This study presents the Yeast Promoter Atlas (YPA, http://ypa.ee.ncku.edu.tw/ or http://ypa.csbb.ntu.edu.tw/) database, which aims to collect comprehensive promoter features in Saccharomyces cerevisiae. YPA integrates nine kinds of promoter features including promoter sequences, genes' transcription boundaries-transcription start sites (TSSs), five prime untranslated regions (5'-UTRs) and three prime untranslated regions (3'UTRs), TATA boxes, transcription factor binding sites (TFBSs), nucleosome occupancy, DNA bendability, transcription factor (TF) binding, TF knockout expression and TF-TF physical interaction. YPA is designed to present data in a unified manner as many important observations are revealed only when these promoter features are considered altogether. For example, DNA rigidity can prevent nucleosome packaging, thereby making TFBSs in the rigid DNA regions more accessible to TFs. Integrating nucleosome occupancy, DNA bendability, TF binding, TF knockout expression and TFBS data helps to identify which TFBS is actually functional. In YPA, various promoter features can be accessed in a centralized and organized platform. Researchers can easily view if the TFBSs in an interested promoter are occupied by nucleosomes or located in a rigid DNA segment and know if the expression of the downstream gene responds to the knockout of the corresponding TFs. Compared to other established yeast promoter databases, YPA collects not only TFBSs but also many other promoter features to help biologists study transcriptional regulation.

  3. Cellular memory of acquired stress resistance in Saccharomyces cerevisiae.

    Science.gov (United States)

    Guan, Qiaoning; Haroon, Suraiya; Bravo, Diego González; Will, Jessica L; Gasch, Audrey P

    2012-10-01

    Cellular memory of past experiences has been observed in several organisms and across a variety of experiences, including bacteria "remembering" prior nutritional status and amoeba "learning" to anticipate future environmental conditions. Here, we show that Saccharomyces cerevisiae maintains a multifaceted memory of prior stress exposure. We previously demonstrated that yeast cells exposed to a mild dose of salt acquire subsequent tolerance to severe doses of H(2)O(2). We set out to characterize the retention of acquired tolerance and in the process uncovered two distinct aspects of cellular memory. First, we found that H(2)O(2) resistance persisted for four to five generations after cells were removed from the prior salt treatment and was transmitted to daughter cells that never directly experienced the pretreatment. Maintenance of this memory did not require nascent protein synthesis after the initial salt pretreatment, but rather required long-lived cytosolic catalase Ctt1p that was synthesized during salt exposure and then distributed to daughter cells during subsequent cell divisions. In addition to and separable from the memory of H(2)O(2) resistance, these cells also displayed a faster gene-expression response to subsequent stress at >1000 genes, representing transcriptional memory. The faster gene-expression response requires the nuclear pore component Nup42p and serves an important function by facilitating faster reacquisition of H(2)O(2) tolerance after a second cycle of salt exposure. Memory of prior stress exposure likely provides a significant advantage to microbial populations living in ever-changing environments.

  4. Sulfate assimilation mediates tellurite reduction and toxicity in Saccharomyces cerevisiae.

    Science.gov (United States)

    Ottosson, Lars-Göran; Logg, Katarina; Ibstedt, Sebastian; Sunnerhagen, Per; Käll, Mikael; Blomberg, Anders; Warringer, Jonas

    2010-10-01

    Despite a century of research and increasing environmental and human health concerns, the mechanistic basis of the toxicity of derivatives of the metalloid tellurium, Te, in particular the oxyanion tellurite, Te(IV), remains unsolved. Here, we provide an unbiased view of the mechanisms of tellurium metabolism in the yeast Saccharomyces cerevisiae by measuring deviations in Te-related traits of a complete collection of gene knockout mutants. Reduction of Te(IV) and intracellular accumulation as metallic tellurium strongly correlated with loss of cellular fitness, suggesting that Te(IV) reduction and toxicity are causally linked. The sulfate assimilation pathway upstream of Met17, in particular, the sulfite reductase and its cofactor siroheme, was shown to be central to tellurite toxicity and its reduction to elemental tellurium. Gene knockout mutants with altered Te(IV) tolerance also showed a similar deviation in tolerance to both selenite and, interestingly, selenomethionine, suggesting that the toxicity of these agents stems from a common mechanism. We also show that Te(IV) reduction and toxicity in yeast is partially mediated via a mitochondrial respiratory mechanism that does not encompass the generation of substantial oxidative stress. The results reported here represent a robust base from which to attack the mechanistic details of Te(IV) toxicity and reduction in a eukaryotic organism.

  5. Tanshinones extend chronological lifespan in budding yeast Saccharomyces cerevisiae.

    Science.gov (United States)

    Wu, Ziyun; Song, Lixia; Liu, Shao Quan; Huang, Dejian

    2014-10-01

    Natural products with anti-aging property have drawn great attention recently but examples of such compounds are exceedingly scarce. By applying a high-throughput assay based on yeast chronological lifespan measurement, we screened the anti-aging activity of 144 botanical materials and found that dried roots of Salvia miltiorrhiza Bunge have significant anti-aging activity. Tanshinones isolated from the plant including cryptotanshione, tanshinone I, and tanshinone IIa, are the active components. Among them, cryptotanshinone can greatly extend the budding yeast Saccharomyces cerevisiae chronological lifespan (up to 2.5 times) in a dose- and the-time-of-addition-dependent manner at nanomolar concentrations without disruption of cell growth. We demonstrate that cryptotanshinone prolong chronological lifespan via a nutrient-dependent regime, especially essential amino acid sensing, and three conserved protein kinases Tor1, Sch9, and Gcn2 are required for cryptotanshinone-induced lifespan extension. In addition, cryptotanshinone significantly increases the lifespan of SOD2-deleted mutants. Altogether, those data suggest that cryptotanshinone might be involved in the regulation of, Tor1, Sch9, Gcn2, and Sod2, these highly conserved longevity proteins modulated by nutrients from yeast to humans.

  6. Xylose Fermentation by Saccharomyces cerevisiae: Challenges and Prospects

    Directory of Open Access Journals (Sweden)

    Danuza Nogueira Moysés

    2016-02-01

    Full Text Available Many years have passed since the first genetically modified Saccharomyces cerevisiae strains capable of fermenting xylose were obtained with the promise of an environmentally sustainable solution for the conversion of the abundant lignocellulosic biomass to ethanol. Several challenges emerged from these first experiences, most of them related to solving redox imbalances, discovering new pathways for xylose utilization, modulation of the expression of genes of the non-oxidative pentose phosphate pathway, and reduction of xylitol formation. Strategies on evolutionary engineering were used to improve fermentation kinetics, but the resulting strains were still far from industrial application. Lignocellulosic hydrolysates proved to have different inhibitors derived from lignin and sugar degradation, along with significant amounts of acetic acid, intrinsically related with biomass deconstruction. This, associated with pH, temperature, high ethanol, and other stress fluctuations presented on large scale fermentations led the search for yeasts with more robust backgrounds, like industrial strains, as engineering targets. Some promising yeasts were obtained both from studies of stress tolerance genes and adaptation on hydrolysates. Since fermentation times on mixed-substrate hydrolysates were still not cost-effective, the more selective search for new or engineered sugar transporters for xylose are still the focus of many recent studies. These challenges, as well as under-appreciated process strategies, will be discussed in this review.

  7. An overview of membrane transport proteins in Saccharomyces cerevisiae.

    Science.gov (United States)

    Andre, B

    1995-12-01

    All eukaryotic cells contain a wide variety of proteins embedded in the plasma and internal membranes, which ensure transmembrane solute transport. It is now established that a large proportion of these transport proteins can be grouped into families apparently conserved throughout organisms. This article presents the data of an in silicio analysis aimed at establishing a preliminary classification of membrane transport proteins in Saccharomyces cerevisiae. This analysis was conducted at a time when about 65% of all yeast genes were available in public databases. In addition to approximately 60 transport proteins whose function was at least partially known, approximately 100 deduced protein sequences of unknown function display significant sequence similarity to membrane transport proteins characterized in yeast and/or other organisms. While some protein families have been well characterized by classical genetic experimental approaches, others have largely if not totally escaped characterization. The proteins revealed by this in silicio analysis also include a putative K+ channel, proteins similar to aquaporins of plant and animal origin, proteins similar to Na+-solute symporters, a protein very similar to electroneural cation-chloride cotransporters, and a putative Na+-H+ antiporter. A new research area is anticipated: the functional analysis of many transport proteins whose existence was revealed by genome sequencing.

  8. Systematic analysis of S. cerevisiae chromosome VIII genes.

    Science.gov (United States)

    Niedenthal, R; Riles, L; Güldener, U; Klein, S; Johnston, M; Hegemann, J H

    1999-12-01

    To begin genome-wide functional analysis, we analysed the consequences of deleting each of the 265 genes of chromosome VIII of Saccharomyces cerevisiae. For 33% of the deletion strains a growth phenotype could be detected: 18% of the genes are essential for growth on complete glucose medium, and 15% grow significantly more slowly than the wild-type strain or exhibit a conditional phenotype when incubated under one of 20 different growth conditions. Two-thirds of the mutants that exhibit conditional phenotypes are pleiotropic; about one-third of the mutants exhibit only one phenotype. We also measured the level of expression directed by the promoter of each gene. About half of the promoters direct detectable transcription in rich glucose medium, and most of these exhibited only low or medium activity. Only 1% of the genes are expressed at about the same level as ACT1. The number of active promoters increased to 76% upon growth on a non-fermentable carbon source, and to 93% in minimal glucose medium. The majority of promoters fluctuated in strength, depending on the medium.

  9. Asparaginyl deamidation in two glutamate dehydrogenase isoenzymes from Saccharomyces cerevisiae.

    Science.gov (United States)

    DeLuna, Alexander; Quezada, Héctor; Gómez-Puyou, Armando; González, Alicia

    2005-03-25

    The non-enzymatic deamidation of asparaginyl residues is a major source of spontaneous damage of several proteins under physiological conditions. In many cases, deamidation and isoaspartyl formation alters the biological activity or stability of the native polypeptide. Rates of deamidation of particular residues depend on many factors including protein structure and solvent exposure. Here, we investigated the spontaneous deamidation of the two NADP-glutamate dehydrogenase isoenzymes from Saccharomyces cerevisiae, which have different kinetic properties and are differentially expressed in this yeast. Our results show that Asn54, present in Gdh3p but missing in the GDH1-encoded homologue, is readily deamidated in vitro under alkaline conditions. Relative to the native enzyme, deamidated Gdh3p shows reduced protein stability. The different deamidation rates of the two isoenzymes could explain to some extent, the relative in vivo instability of the allosteric Gdh3p enzyme, compared to that of Gdh1p. It is thus possible that spontaneous asparaginyl modification could play a role in the metabolic regulation of ammonium assimilation and glutamate biosynthesis.

  10. Regulation by ammonium of glutamate dehydrogenase (NADP+) from Saccharomyces cerevisiae.

    Science.gov (United States)

    Bogonez, E; Satrústegui, J; Machado, A

    1985-06-01

    The activity of glutamate dehydrogenase (NADP+) (EC 1.4.1.4; NADP-GDH) of Saccharomyces cerevisiae is decreased under conditions in which intracellular ammonia concentrations increases. A high internal ammonia concentration can be obtained (a) by increasing the ammonium sulphate concentration in the culture medium, and (b) by growing the yeast either in acetate + ammonia media, where the pH of the medium rises during growth, or in heavily buffered glucose + ammonia media at pH 7.5. Under these conditions cellular oxoglutarate concentrations do not vary and changes in NADP-GDH activity appear to provide a constant rate of oxoglutarate utilization. The following results suggest that the decrease in NADP-GDH activity in ammonia-accumulating yeast cells is brought about by repression of synthesis: (i) after a shift to high ammonium sulphate concentrations, the number of units of activity per cell decreased as the inverse of cell doubling; and (ii) the rate of degradation of labelled NADP-GDH was essentially the same in ammonia-accumulating yeast cells and in controls, whereas the synthesis constant was much lower in the ammonia-accumulating cells than in the controls.

  11. Rapid Identification of Chemical Genetic Interactions in Saccharomyces cerevisiae

    Science.gov (United States)

    Dilworth, David; Nelson, Christopher J.

    2015-01-01

    Determining the mode of action of bioactive chemicals is of interest to a broad range of academic, pharmaceutical, and industrial scientists. Saccharomyces cerevisiae, or budding yeast, is a model eukaryote for which a complete collection of ~6,000 gene deletion mutants and hypomorphic essential gene mutants are commercially available. These collections of mutants can be used to systematically detect chemical-gene interactions, i.e. genes necessary to tolerate a chemical. This information, in turn, reports on the likely mode of action of the compound. Here we describe a protocol for the rapid identification of chemical-genetic interactions in budding yeast. We demonstrate the method using the chemotherapeutic agent 5-fluorouracil (5-FU), which has a well-defined mechanism of action. Our results show that the nuclear TRAMP RNA exosome and DNA repair enzymes are needed for proliferation in the presence of 5-FU, which is consistent with previous microarray based bar-coding chemical genetic approaches and the knowledge that 5-FU adversely affects both RNA and DNA metabolism. The required validation protocols of these high-throughput screens are also described. PMID:25867090

  12. Carboxylic Acids Plasma Membrane Transporters in Saccharomyces cerevisiae.

    Science.gov (United States)

    Casal, Margarida; Queirós, Odília; Talaia, Gabriel; Ribas, David; Paiva, Sandra

    2016-01-01

    This chapter covers the functionally characterized plasma membrane carboxylic acids transporters Jen1, Ady2, Fps1 and Pdr12 in the yeast Saccharomyces cerevisiae, addressing also their homologues in other microorganisms, as filamentous fungi and bacteria. Carboxylic acids can either be transported into the cells, to be used as nutrients, or extruded in response to acid stress conditions. The secondary active transporters Jen1 and Ady2 can mediate the uptake of the anionic form of these substrates by a H(+)-symport mechanism. The undissociated form of carboxylic acids is lipid-soluble, crossing the plasma membrane by simple diffusion. Furthermore, acetic acid can also be transported by facilitated diffusion via Fps1 channel. At the cytoplasmic physiological pH, the anionic form of the acid prevails and it can be exported by the Pdr12 pump. This review will highlight the mechanisms involving carboxylic acids transporters, and the way they operate according to the yeast cell response to environmental changes, as carbon source availability, extracellular pH and acid stress conditions.

  13. D-xylulose fermentation to ethanol by Saccharomyces cerevisiae

    Energy Technology Data Exchange (ETDEWEB)

    Chiang, L.C.; Gong, C.S.; Chen, L.F.; Tsao, G.T.

    1981-08-01

    Commercial bakers' yeast (Saccharomyces cerevisiae) was used to study the conversion of D-xylulose to ethanol in the presence of D-xylose. The rate of ethanol production increased with an increase in yeast cell density. The optimal temperature for D-xylulose fermentation was 35 degrees Celcius, and the optimal pH range was 4 to 6. The fermentation of D-xylulose by yeast resulted in the production of ethanol as the major product; small amounts of xylitol and glycerol were also produced. The production of xylitol was influenced by pH as well as temperature. High pH values and low temperatures enhanced xylitol production. The rate of D-xylulose fermentation decreased when the production of ethanol yielded concentrations of 4% or more. The slow conversion rate of D-xylulose to ethanol was increased by increasing the yeast cell density. The overall production of ethanol from D-xylulose by yeast cells under optimal conditions was 90% of the theoretical yield. (Refs. 21).

  14. mRNA quality control pathways in Saccharomyces cerevisiae

    Indian Academy of Sciences (India)

    Satarupa Das; Biswadip Das

    2013-09-01

    Efficient production of translation-competent mRNAs involves processing and modification events both in the nucleus and cytoplasm which require a number of complex machineries at both co-transcriptional and post-transcriptional levels. Mutations in the genomic sequence sometimes result in the formation of mutant non-functional defective messages. In addition, the enormous amounts of complexities involved in the biogenesis of mRNPs in the nucleus very often leads to the formation of aberrant and faulty messages along with their functional counterpart. Subsequent translation of these mutant and defective populations of messenger RNAs could possibly result in the unfaithful transmission of genetic information and thus is considered a threat to the survival of the cell. To prevent this possibility, mRNA quality control systems have evolved both in the nucleus and cytoplasm in eukaryotes to scrutinize various stages of mRNP biogenesis and translation. In this review, we will focus on the physiological role of some of these mRNA quality control systems in the simplest model eukaryote Saccharomyces cerevisiae.

  15. Direct mating between diploid sake strains of Saccharomyces cerevisiae.

    Science.gov (United States)

    Hashimoto, Shinji; Aritomi, Kazuo; Minohara, Takafumi; Nishizawa, Yoshinori; Hoshida, Hisashi; Kashiwagi, Susumu; Akada, Rinji

    2006-02-01

    Various auxotrophic mutants of diploid heterothallic Japanese sake strains of Saccharomyces cerevisiae were utilized for selecting mating-competent diploid isolates. The auxotrophic mutants were exposed to ultraviolet (UV) irradiation and crossed with laboratory haploid tester strains carrying complementary auxotrophic markers. Zygotes were then selected on minimal medium. Sake strains exhibiting a MATa or MATalpha mating type were easily obtained at high frequency without prior sporulation, suggesting that the UV irradiation induced homozygosity at the MAT locus. Flow cytometric analysis of a hybrid showed a twofold higher DNA content than the sake diploid parent, consistent with tetraploidy. By crossing strains of opposite mating type in all possible combinations, a number of hybrids were constructed. Hybrids formed in crosses between traditional sake strains and between a natural nonhaploid isolate and traditional sake strains displayed equivalent fermentation ability without any apparent defects and produced comparable or improved sake. Isolation of mating-competent auxotrophic mutants directly from industrial yeast strains allows crossbreeding to construct polyploids suitable for industrial use without dependence on sporulation.

  16. Regulation of the Saccharomyces cerevisiae DNA repair gene RAD16.

    Science.gov (United States)

    Bang, D D; Timmermans, V; Verhage, R; Zeeman, A M; van de Putte, P; Brouwer, J

    1995-05-25

    The RAD16 gene product has been shown to be essential for the repair of the silenced mating type loci [Bang et al. (1992) Nucleic Acids Res. 20, 3925-3931]. More recently we demonstrated that the RAD16 and RAD7 proteins are also required for repair of non-transcribed strands of active genes in Saccharomyces cerevisiae [Waters et al. (1993) Mol. Gen. Genet. 239, 28-32]. We have studied the regulation of the RAD16 gene and found that the RAD16 transcript levels increased up to 7-fold upon UV irradiation. Heat shock at 42 degrees C also results in elevated levels of RAD16 mRNA. In sporulating MAT alpha/MATa diploid cells RAD16 mRNA is also induced. The basal level of the RAD16 transcript is constant during the mitotic cell cycle. G1-arrested cells show normal induction of RAD16 mRNA upon UV irradiation demonstrating that the induction is not a secondary consequence of G2 cell cycle arrest following UV irradiation. However, in cells arrested in G1 the induction of RAD16 mRNA after UV irradiation is not followed by a rapid decline as occurs in normal growing cells suggesting that the down regulation of RAD16 transcription is dependent on progression into the cell cycle.

  17. Single-nucleosome mapping of histone modifications in S. cerevisiae.

    Directory of Open Access Journals (Sweden)

    Chih Long Liu

    2005-10-01

    Full Text Available Covalent modification of histone proteins plays a role in virtually every process on eukaryotic DNA, from transcription to DNA repair. Many different residues can be covalently modified, and it has been suggested that these modifications occur in a great number of independent, meaningful combinations. Published low-resolution microarray studies on the combinatorial complexity of histone modification patterns suffer from confounding effects caused by the averaging of modification levels over multiple nucleosomes. To overcome this problem, we used a high-resolution tiled microarray with single-nucleosome resolution to investigate the occurrence of combinations of 12 histone modifications on thousands of nucleosomes in actively growing S. cerevisiae. We found that histone modifications do not occur independently; there are roughly two groups of co-occurring modifications. One group of lysine acetylations shows a sharply defined domain of two hypo-acetylated nucleosomes, adjacent to the transcriptional start site, whose occurrence does not correlate with transcription levels. The other group consists of modifications occurring in gradients through the coding regions of genes in a pattern associated with transcription. We found no evidence for a deterministic code of many discrete states, but instead we saw blended, continuous patterns that distinguish nucleosomes at one location (e.g., promoter nucleosomes from those at another location (e.g., over the 3' ends of coding regions. These results are consistent with the idea of a simple, redundant histone code, in which multiple modifications share the same role.

  18. MAP kinase pathways in the yeast Saccharomyces cerevisiae

    Science.gov (United States)

    Gustin, M. C.; Albertyn, J.; Alexander, M.; Davenport, K.; McIntire, L. V. (Principal Investigator)

    1998-01-01

    A cascade of three protein kinases known as a mitogen-activated protein kinase (MAPK) cascade is commonly found as part of the signaling pathways in eukaryotic cells. Almost two decades of genetic and biochemical experimentation plus the recently completed DNA sequence of the Saccharomyces cerevisiae genome have revealed just five functionally distinct MAPK cascades in this yeast. Sexual conjugation, cell growth, and adaptation to stress, for example, all require MAPK-mediated cellular responses. A primary function of these cascades appears to be the regulation of gene expression in response to extracellular signals or as part of specific developmental processes. In addition, the MAPK cascades often appear to regulate the cell cycle and vice versa. Despite the success of the gene hunter era in revealing these pathways, there are still many significant gaps in our knowledge of the molecular mechanisms for activation of these cascades and how the cascades regulate cell function. For example, comparison of different yeast signaling pathways reveals a surprising variety of different types of upstream signaling proteins that function to activate a MAPK cascade, yet how the upstream proteins actually activate the cascade remains unclear. We also know that the yeast MAPK pathways regulate each other and interact with other signaling pathways to produce a coordinated pattern of gene expression, but the molecular mechanisms of this cross talk are poorly understood. This review is therefore an attempt to present the current knowledge of MAPK pathways in yeast and some directions for future research in this area.

  19. Calcium dependence of eugenol tolerance and toxicity in Saccharomyces cerevisiae.

    Science.gov (United States)

    Roberts, Stephen K; McAinsh, Martin; Cantopher, Hanna; Sandison, Sean

    2014-01-01

    Eugenol is a plant-derived phenolic compound which has recognised therapeutical potential as an antifungal agent. However little is known of either its fungicidal activity or the mechanisms employed by fungi to tolerate eugenol toxicity. A better exploitation of eugenol as a therapeutic agent will therefore depend on addressing this knowledge gap. Eugenol initiates increases in cytosolic Ca2+ in Saccharomyces cerevisiae which is partly dependent on the plasma membrane calcium channel, Cch1p. However, it is unclear whether a toxic cytosolic Ca2+elevation mediates the fungicidal activity of eugenol. In the present study, no significant difference in yeast survival was observed following transient eugenol treatment in the presence or absence of extracellular Ca2+. Furthermore, using yeast expressing apoaequorin to report cytosolic Ca2+ and a range of eugenol derivatives, antifungal activity did not appear to be coupled to Ca2+ influx or cytosolic Ca2+ elevation. Taken together, these results suggest that eugenol toxicity is not dependent on a toxic influx of Ca2+. In contrast, careful control of extracellular Ca2+ (using EGTA or BAPTA) revealed that tolerance of yeast to eugenol depended on Ca2+ influx via Cch1p. These findings expose significant differences between the antifungal activity of eugenol and that of azoles, amiodarone and carvacrol. This study highlights the potential to use eugenol in combination with other antifungal agents that exhibit differing modes of action as antifungal agents to combat drug resistant infections.

  20. Ecological and Genetic Barriers Differentiate Natural Populations of Saccharomyces cerevisiae.

    Science.gov (United States)

    Clowers, Katie J; Heilberger, Justin; Piotrowski, Jeff S; Will, Jessica L; Gasch, Audrey P

    2015-09-01

    How populations that inhabit the same geographical area become genetically differentiated is not clear. To investigate this, we characterized phenotypic and genetic differences between two populations of Saccharomyces cerevisiae that in some cases inhabit the same environment but show relatively little gene flow. We profiled stress sensitivity in a group of vineyard isolates and a group of oak-soil strains and found several niche-related phenotypes that distinguish the populations. We performed bulk-segregant mapping on two of the distinguishing traits: The vineyard-specific ability to grow in grape juice and oak-specific tolerance to the cell wall damaging drug Congo red. To implicate causal genes, we also performed a chemical genomic screen in the lab-strain deletion collection and identified many important genes that fell under quantitative trait loci peaks. One gene important for growth in grape juice and identified by both the mapping and the screen was SSU1, a sulfite-nitrite pump implicated in wine fermentations. The beneficial allele is generated by a known translocation that we reasoned may also serve as a genetic barrier. We found that the translocation is prevalent in vineyard strains, but absent in oak strains, and presents a postzygotic barrier to spore viability. Furthermore, the translocation was associated with a fitness cost to the rapid growth rate seen in oak-soil strains. Our results reveal the translocation as a dual-function locus that enforces ecological differentiation while producing a genetic barrier to gene flow in these sympatric populations.

  1. Metabolic engineering of Saccharomyces cerevisiae for production of ginsenosides.

    Science.gov (United States)

    Dai, Zhubo; Liu, Yi; Zhang, Xianan; Shi, Mingyu; Wang, Beibei; Wang, Dong; Huang, Luqi; Zhang, Xueli

    2013-11-01

    Ginsenosides are the primary bioactive components of ginseng, which is a popular medicinal herb and exhibits diverse pharmacological activities. Protopanaxadiol is the aglycon of several dammarane-type ginsenosides, which also has anticancer activity. For microbial production of protopanaxadiol, dammarenediol-II synthase and protopanaxadiol synthase genes of Panax ginseng, together with a NADPH-cytochrome P450 reductase gene of Arabidopsis thaliana, were introduced into Saccharomyces cerevisiae, resulting in production of 0.05 mg/g DCW protopanaxadiol. Increasing squalene and 2,3-oxidosqualene supplies through overexpressing truncated 3-hydroxyl-3-methylglutaryl-CoA reductase, farnesyl diphosphate synthase, squalene synthase and 2,3-oxidosqualene synthase genes, together with increasing protopanaxadiol synthase activity through codon optimization, led to 262-fold increase of protopanaxadiol production. Finally, using two-phase extractive fermentation resulted in production of 8.40 mg/g DCW protopanaxadiol (1189 mg/L), together with 10.94 mg/g DCW dammarenediol-II (1548 mg/L). The yeast strains engineered in this work can serve as the basis for creating an alternative way for production of ginsenosides in place of extraction from plant sources.

  2. Calcium dependence of eugenol tolerance and toxicity in Saccharomyces cerevisiae.

    Directory of Open Access Journals (Sweden)

    Stephen K Roberts

    Full Text Available Eugenol is a plant-derived phenolic compound which has recognised therapeutical potential as an antifungal agent. However little is known of either its fungicidal activity or the mechanisms employed by fungi to tolerate eugenol toxicity. A better exploitation of eugenol as a therapeutic agent will therefore depend on addressing this knowledge gap. Eugenol initiates increases in cytosolic Ca2+ in Saccharomyces cerevisiae which is partly dependent on the plasma membrane calcium channel, Cch1p. However, it is unclear whether a toxic cytosolic Ca2+elevation mediates the fungicidal activity of eugenol. In the present study, no significant difference in yeast survival was observed following transient eugenol treatment in the presence or absence of extracellular Ca2+. Furthermore, using yeast expressing apoaequorin to report cytosolic Ca2+ and a range of eugenol derivatives, antifungal activity did not appear to be coupled to Ca2+ influx or cytosolic Ca2+ elevation. Taken together, these results suggest that eugenol toxicity is not dependent on a toxic influx of Ca2+. In contrast, careful control of extracellular Ca2+ (using EGTA or BAPTA revealed that tolerance of yeast to eugenol depended on Ca2+ influx via Cch1p. These findings expose significant differences between the antifungal activity of eugenol and that of azoles, amiodarone and carvacrol. This study highlights the potential to use eugenol in combination with other antifungal agents that exhibit differing modes of action as antifungal agents to combat drug resistant infections.

  3. Allosteric interactions of DNA and nucleotides with S. cerevisiae RSC.

    Science.gov (United States)

    Malik, Shuja Shafi; Rich, Evan; Viswanathan, Ramya; Cairns, Bradley R; Fischer, Christopher J

    2011-09-20

    RSC (remodel the structure of chromatin) is an essential chromatin remodeler of Saccharomyces cerevisiae that has been shown to have DNA translocase properties. We studied the DNA binding properties of a "trimeric minimal RSC" (RSCt) of the RSC chromatin remodeling complex and the effect of nucleotides on this interaction using fluorescence anisotropy. RSCt binds to 20 bp fluorescein-labeled double-stranded DNA with a K(d) of ∼100 nM. The affinity of RSCt for DNA is reduced in the presence of AMP-PNP and ADP in a concentration-dependent manner with the addition of AMP-PNP having more pronounced effect. These differences in the magnitude at which the binding of ADP and AMP-PNP affects the affinity of DNA binding by RSCt suggest that the physical movement of the enzyme along DNA begins between the binding of ATP and its subsequent hydrolysis. Furthermore, the fact that the highest affinity for DNA binding by RSCt occurs in the absence of bound nucleotide offers a mechanistic explanation for the apparent low processivity of DNA translocation by the enzyme.

  4. Metabolic engineering of Saccharomyces cerevisiae for caffeine and theobromine production.

    Science.gov (United States)

    Jin, Lu; Bhuiya, Mohammad Wadud; Li, Mengmeng; Liu, XiangQi; Han, Jixiang; Deng, WeiWei; Wang, Min; Yu, Oliver; Zhang, Zhengzhu

    2014-01-01

    Caffeine (1, 3, 7-trimethylxanthine) and theobromine (3, 7-dimethylxanthine) are the major purine alkaloids in plants, e.g., tea (Camellia sinensis) and coffee (Coffea arabica). Caffeine is a major component of coffee and is used widely in food and beverage industries. Most of the enzymes involved in the caffeine biosynthetic pathway have been reported previously. Here, we demonstrated the biosynthesis of caffeine (0.38 mg/L) by co-expression of Coffea arabica xanthosine methyltransferase (CaXMT) and Camellia sinensis caffeine synthase (TCS) in Saccharomyces cerevisiae. Furthermore, we endeavored to develop this production platform for making other purine-based alkaloids. To increase the catalytic activity of TCS in an effort to increase theobromine production, we identified four amino acid residues based on structural analyses of 3D-model of TCS. Two TCS1 mutants (Val317Met and Phe217Trp) slightly increased in theobromine accumulation and simultaneously decreased in caffeine production. The application and further optimization of this biosynthetic platform are discussed.

  5. Metabolic engineering of Saccharomyces cerevisiae for caffeine and theobromine production.

    Directory of Open Access Journals (Sweden)

    Lu Jin

    Full Text Available Caffeine (1, 3, 7-trimethylxanthine and theobromine (3, 7-dimethylxanthine are the major purine alkaloids in plants, e.g., tea (Camellia sinensis and coffee (Coffea arabica. Caffeine is a major component of coffee and is used widely in food and beverage industries. Most of the enzymes involved in the caffeine biosynthetic pathway have been reported previously. Here, we demonstrated the biosynthesis of caffeine (0.38 mg/L by co-expression of Coffea arabica xanthosine methyltransferase (CaXMT and Camellia sinensis caffeine synthase (TCS in Saccharomyces cerevisiae. Furthermore, we endeavored to develop this production platform for making other purine-based alkaloids. To increase the catalytic activity of TCS in an effort to increase theobromine production, we identified four amino acid residues based on structural analyses of 3D-model of TCS. Two TCS1 mutants (Val317Met and Phe217Trp slightly increased in theobromine accumulation and simultaneously decreased in caffeine production. The application and further optimization of this biosynthetic platform are discussed.

  6. The network architecture of the Saccharomyces cerevisiae genome.

    Directory of Open Access Journals (Sweden)

    Stephen A Hoang

    Full Text Available We propose a network-based approach for surmising the spatial organization of genomes from high-throughput interaction data. Our strategy is based on methods for inferring architectural features of networks. Specifically, we employ a community detection algorithm to partition networks of genomic interactions. These community partitions represent an intuitive interpretation of genomic organization from interaction data. Furthermore, they are able to recapitulate known aspects of the spatial organization of the Saccharomyces cerevisiae genome, such as the rosette conformation of the genome, the clustering of centromeres, as well as tRNAs, and telomeres. We also demonstrate that simple architectural features of genomic interaction networks, such as cliques, can give meaningful insight into the functional role of the spatial organization of the genome. We show that there is a correlation between inter-chromosomal clique size and replication timing, as well as cohesin enrichment. Together, our network-based approach represents an effective and intuitive framework for interpreting high-throughput genomic interaction data. Importantly, there is a great potential for this strategy, given the rich literature and extensive set of existing tools in the field of network analysis.

  7. ORGANIC ACIDS CONCENTRATION IN WINE STOCKS AFTER Saccharomyces cerevisiae FERMENTATION

    Directory of Open Access Journals (Sweden)

    V. N. Bayraktar

    2013-04-01

    Full Text Available The biochemical constituents in wine stocks that influence the flavor and quality of wine are investigated in the paper. The tested parameters consist of volume fraction of ethanol, residual sugar, phenolic compounds, tartaric, malic, citric, lactic, acetic acids, titratable acidity and volatile acids. The wine stocks that were received from white and red grape varieties Tairov`s selection were tested. There was a correlation between titratable acidity and volatile acids in the wine stocks from white and red grape varieties. High correlation was also found between lactic and acetic acids, between volatile acids, acetic acid and sugar. It was determined that wine stocks with a high concentration of ethanol originated from those yeast strains of Saccharomyces cerevisiae, in a fermented grape must of high speed of enzyme activity. The taste of wine stocks correlated with the ratio of tartaric to malic acid. Analysis showed significant differences between the varieties of white and red wine stocks in concentrations of organic acids, phenolic compounds, residual sugar, and volume fraction of ethanol. Positive correlation was indicated for both studied groups for volatile acids and acetic acid, tartaric, malic, lactic acids and total sugar. Prospective yeast cultures with high productivity of alcohol (ethanol were selected for winemaking biotechnology.

  8. Metabolically engineered Saccharomyces cerevisiae for branched-chain ester productions.

    Science.gov (United States)

    Yuan, Jifeng; Mishra, Pranjul; Ching, Chi Bun

    2016-12-10

    Medium branched-chain esters can be used not only as a biofuel but are also useful chemicals with various industrial applications. The development of economically feasible and environment friendly bio-based fuels requires efficient cell factories capable of producing desired products in high yield. Herein, we sought to use a number of strategies to engineer Saccharomyces cerevisiae for high-level production of branched-chain esters. Mitochondrion-based expression of ATF1 gene in a base strain with an overexpressed valine biosynthetic pathway together with expression of mitochondrion-relocalized α-ketoacid decarboxylase (encoded by ARO10) and alcohol dehydrogenase (encoded by ADH7) not only produced isobutyl acetate, but also 3-methyl-1-butyl acetate and 2-methyl-1-butyl acetate. Further segmentation of the downstream esterification step into the cytosol to utilize the cytosolic acetyl-CoA pool for acetyltransferase (ATF)-mediated condensation enabled an additional fold improvement of ester productions. The best titre attained in the present study is 260.2mg/L isobutyl acetate, 296.1mg/L 3-methyl-1-butyl acetate and 289.6mg/L 2-methyl-1-butyl acetate.

  9. Data on dynamic study of cytoophidia in Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    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.

  10. Assembly of evolved ligninolytic genes in Saccharomyces cerevisiae

    Science.gov (United States)

    Gonzalez-Perez, David; Alcalde, Miguel

    2014-01-01

    The ligninolytic enzymatic consortium produced by white-rot fungi is one of the most efficient oxidative systems found in nature, with many potential applications that range from the production of 2nd generation biofuels to chemicals synthesis. In the current study, two high redox potential oxidoreductase fusion genes (laccase -Lac- and versatile peroxidase -Vp-) that had been evolved in the laboratory were re-assembled in Saccharomyces cerevisiae. First, cell viability and secretion were assessed after co-transforming the Lac and Vp genes into yeast. Several expression cassettes were inserted in vivo into episomal bi-directional vectors in order to evaluate inducible promoter and/or terminator pairs of different strengths in an individual and combined manner. The synthetic white-rot yeast model harboring Vp(GAL1/CYC1)-Lac(GAL10/ADH1) displayed up to 1000 and 100 Units per L of peroxidase and laccase activity, respectively, representing a suitable point of departure for future synthetic biology studies. PMID:24830983

  11. Bread, beer and wine: Saccharomyces cerevisiae diversity reflects human history.

    Science.gov (United States)

    Legras, Jean-Luc; Merdinoglu, Didier; Cornuet, Jean-Marie; Karst, Francis

    2007-05-01

    Fermented beverages and foods have played a significant role in most societies worldwide for millennia. To better understand how the yeast species Saccharomyces cerevisiae, the main fermenting agent, evolved along this historical and expansion process, we analysed the genetic diversity among 651 strains from 56 different geographical origins, worldwide. Their genotyping at 12 microsatellite loci revealed 575 distinct genotypes organized in subgroups of yeast types, i.e. bread, beer, wine, sake. Some of these groups presented unexpected relatedness: Bread strains displayed a combination of alleles intermediate between beer and wine strains, and strains used for rice wine and sake were most closely related to beer and bread strains. However, up to 28% of genetic diversity between these technological groups was associated with geographical differences which suggests local domestications. Focusing on wine yeasts, a group of Lebanese strains were basal in an F(ST) tree, suggesting a Mesopotamia-based origin of most wine strains. In Europe, migration of wine strains occurred through the Danube Valley, and around the Mediterranean Sea. An approximate Bayesian computation approach suggested a postglacial divergence (most probable period 10,000-12,000 bp). As our results suggest intimate association between man and wine yeast across centuries, we hypothesize that yeast followed man and vine migrations as a commensal member of grapevine flora.

  12. 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

    Biofilm-forming microorganisms switch between two forms: free-living planktonic and sessile multicellular. Sessile communities of yeast biofilms in liquid medium provide a primitive example of multicellularity and are clinically important because biofilms tend to have other growth characteristics...... 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...... northern blots further revealed that AIM1, ASG1, AVT1, DRN1, ELP4, FLO8, FMP10, HMT1, KAR5, MIT1, MRPL32, MSS11, NCP1, NPR1, PEP5, PEX25, RIM8, RIM101, RGT1, SNF8, SPC2, STB6, STP22, TEC1, VID24, VPS20, VTC3, YBL029W, YBL029C-A, YFL054C, YGR161W-C, YIL014C-A, YIR024C, YKL151C, YNL200C, YOR034C-A, and YOR...

  13. Dominance of Saccharomyces cerevisiae in alcoholic fermentation processes: role of physiological fitness and microbial interactions.

    Science.gov (United States)

    Albergaria, Helena; Arneborg, Nils

    2016-03-01

    Winemaking, brewing and baking are some of the oldest biotechnological processes. In all of them, alcoholic fermentation is the main biotransformation and Saccharomyces cerevisiae the primary microorganism. Although a wide variety of microbial species may participate in alcoholic fermentation and contribute to the sensory properties of end-products, the yeast S. cerevisiae invariably dominates the final stages of fermentation. The ability of S. cerevisiae to outcompete other microbial species during alcoholic fermentation processes, such as winemaking, has traditionally been ascribed to its high fermentative power and capacity to withstand the harsh environmental conditions, i.e. high levels of ethanol and organic acids, low pH values, scarce oxygen availability and depletion of certain nutrients. However, in recent years, several studies have raised evidence that S. cerevisiae, beyond its remarkable fitness for alcoholic fermentation, also uses defensive strategies mediated by different mechanisms, such as cell-to-cell contact and secretion of antimicrobial peptides, to combat other microorganisms. In this paper, we review the main physiological features underlying the special aptitude of S. cerevisiae for alcoholic fermentation and discuss the role of microbial interactions in its dominance during alcoholic fermentation, as well as its relevance for winemaking.

  14. Bioethanol production from Gracilaria verrucosa using Saccharomyces cerevisiae adapted to NaCl or galactose.

    Science.gov (United States)

    Nguyen, Trung Hau; Ra, Chae Hun; Sunwoo, InYung; Jeong, Gwi-Taek; Kim, Sung-Koo

    2016-12-18

    This study examined the pretreatment, enzymatic saccharification, and fermentation of the red macroalgae Gracilaria verrucosa using adapted saccharomyces cerevisiae to galactose or NaCl for the increase of bioethanol yield. Pretreatment with thermal acid hydrolysis to obtain galactose was carried out with 11.7% (w/v) seaweed slurry and 373 mM H2SO4 at 121 °C for 59 min. Glucose was obtained from enzymatic hydrolysis. Enzymatic saccharification was performed with a mixture of 16 U/mL Celluclast 1.5L and Viscozyme L at 45 °C for 48 h. Ethanol fermentation in 11.7% (w/v) seaweed hydrolysate was carried out using Saccharomyces cerevisiae KCTC 1126 adapted or non-adapted to high concentrations of galactose or NaCl. When non-adapted S. cerevisiae KCTC 1126 was used, the ethanol productivity was 0.09 g/(Lh) with an ethanol yield of 0.25. Ethanol productivity of 0.16 and 0.19 g/(Lh) with ethanol yields of 0.43 and 0.48 was obtained using S. cerevisiae KCTC 1126 adapted to high concentrations of galactose and NaCl, respectively. Adaptation of S. cerevisiae KCTC 1126 to galactose or NaCl increased the ethanol yield via adaptive evolution of the yeast.

  15. Screening of Non- Saccharomyces cerevisiae Strains for Tolerance to Formic Acid in Bioethanol Fermentation.

    Science.gov (United States)

    Oshoma, Cyprian E; Greetham, Darren; Louis, Edward J; Smart, Katherine A; Phister, Trevor G; Powell, Chris; Du, Chenyu

    2015-01-01

    Formic acid is one of the major inhibitory compounds present in hydrolysates derived from lignocellulosic materials, the presence of which can significantly hamper the efficiency of converting available sugars into bioethanol. This study investigated the potential for screening formic acid tolerance in non-Saccharomyces cerevisiae yeast strains, which could be used for the development of advanced generation bioethanol processes. Spot plate and phenotypic microarray methods were used to screen the formic acid tolerance of 7 non-Saccharomyces cerevisiae yeasts. S. kudriavzeii IFO1802 and S. arboricolus 2.3319 displayed a higher formic acid tolerance when compared to other strains in the study. Strain S. arboricolus 2.3319 was selected for further investigation due to its genetic variability among the Saccharomyces species as related to Saccharomyces cerevisiae and availability of two sibling strains: S. arboricolus 2.3317 and 2.3318 in the lab. The tolerance of S. arboricolus strains (2.3317, 2.3318 and 2.3319) to formic acid was further investigated by lab-scale fermentation analysis, and compared with S. cerevisiae NCYC2592. S. arboricolus 2.3319 demonstrated improved formic acid tolerance and a similar bioethanol synthesis capacity to S. cerevisiae NCYC2592, while S. arboricolus 2.3317 and 2.3318 exhibited an overall inferior performance. Metabolite analysis indicated that S. arboricolus strain 2.3319 accumulated comparatively high concentrations of glycerol and glycogen, which may have contributed to its ability to tolerate high levels of formic acid.

  16. Mixing of vineyard and oak-tree ecotypes of Saccharomyces cerevisiae in North American vineyards.

    Science.gov (United States)

    Hyma, Katie E; Fay, Justin C

    2013-06-01

    Humans have had a significant impact on the distribution and abundance of Saccharomyces cerevisiae through its widespread use in beer, bread and wine production. Yet, similar to other Saccharomyces species, S. cerevisiae has also been isolated from habitats unrelated to fermentations. Strains of S. cerevisiae isolated from grapes, wine must and vineyards worldwide are genetically differentiated from strains isolated from oak-tree bark, exudate and associated soil in North America. However, the causes and consequences of this differentiation have not yet been resolved. Historical differentiation of these two groups may have been influenced by geographic, ecological or human-associated barriers to gene flow. Here, we make use of the relatively recent establishment of vineyards across North America to identify and characterize any active barriers to gene flow between these two groups. We examined S. cerevisiae strains isolated from grapes and oak trees within three North American vineyards and compared them to those isolated from oak trees outside of vineyards. Within vineyards, we found evidence of migration between grapes and oak trees and potential gene flow between the divergent oak-tree and vineyard groups. Yet, we found no vineyard genotypes on oak trees outside of vineyards. In contrast, Saccharomyces paradoxus isolated from the same sources showed population structure characterized by isolation by distance. The apparent absence of ecological or genetic barriers between sympatric vineyard and oak-tree populations of S. cerevisiae implies that vineyards play an important role in the mixing between these two groups.

  17. Effects of sequential mixed cultures of Wickerhamomyces anomalus and Saccharomyces cerevisiae on apple cider fermentation.

    Science.gov (United States)

    Ye, Mengqi; Yue, Tianli; Yuan, Yahong

    2014-09-01

    The fermentation of cider by mixed cultures of Wickerhamomyces anomalus and Saccharomyces cerevisiae was carried out to study their effect on the cider quality. The results showed that growth of W. anomalus and S. cerevisiae was affected by each other during co-fermentation process. All the mixed cultures produced statistically the same level of ethanol as S. cerevisiae monoculture. The mixed fermentation could produce more variety and higher amounts of acetate esters, ethyl esters, higher alcohols, aldehydes, and ketones. Sensory evaluation demonstrated that ciders obtained from co-fermentation with W. anomalus gained higher scores than ciders fermented by pure S. cerevisiae, especially the co-fermentation cultures WS3, WS4, WS6, and WS8. Only 3 days of fermentation with W. anomalus in sequential mixtures were enough to improve the quality of cider. Wickerhamomyces anomalus could be used in association with S. cerevisiae to improve the quality of cider. The modulation of inoculation time may provide an effective means of manipulating cider aroma for different characteristics.

  18. Genotoxicity of <em>Euphorbia hirtaem>: An <em>Allium cepaem> Assay

    Directory of Open Access Journals (Sweden)

    Kwan Yuet Ping

    2012-06-01

    Full Text Available The potential genotoxic effects of methanolic extracts of <em>Euphorbia hirta em>which is commonly used in traditional medicine to treat a variety of diseased conditions including asthma, coughs, diarrhea and dysentery was investigated using <em>Allium cepaem> assay. The extracts of 125, 250, 500 and 1,000 µg/mL were tested on root meristems of <em>A. cepaem>. Ethylmethanesulfonate was used as positive control and distilled water was used as negative control. The result showed that mitotic index decreased as the concentrations of <em>E. hirtaem> extract increased. A dose-dependent increase of chromosome aberrations was also observed. Abnormalities scored were stickiness, c-mitosis, bridges and vagrant chromosomes. Micronucleated cells were also observed at interphase. Result of this study confirmed that the methanol extracts of <em>E. hirta em>exerted significant genotoxic and mitodepressive effects at 1,000 µg/mL.

  19. <em>In Vitroem> Antioxidant Properties of Flavonoids and Polysaccharides Extract from Tobacco (<em>Nicotiana> em>tabacum> L. Leaves

    Directory of Open Access Journals (Sweden)

    Jing-Lu Wang

    2012-09-01

    Full Text Available In the present study, antioxidant properties of flavonoids and polysaccharides from tobacco (<em>Nicotiana> tabacumem> L. leaves were evaluated in several <em>in vitroem> systems, e.g., scavenging activities on hydroxyl, superoxide anion, 1,1-diphenyl-2-picrylhydrazyl (DPPH and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid (ABTS radicals, and reducing power. Flavonoids showed much better activity than polysaccharides in scavenging activities on free radicals. When compared to the positive control, ascorbic acid, both showed weaker antioxidant potential. However, flavonoids possessed comparable superoxide anion, DPPH and ABTS radical scavenging abilities to ascorbic acid at high concentration (600 μg/mL. Meanwhile, it was found that flavonoids had prominent effects on the reducing power, which was equivalent to ascorbic acid, and was significantly higher than polysaccharides. These results clearly indicate that flavonoids are effective in scavenging free radicals and have the potential to be powerful antioxidants. Thus, tobacco leaves could be considered as a potential source of natural antioxidants for food, pharmaceutical, cosmetics or nutraceutical industries.

  20. Overexpression of Erg11p by the Regulatable GAL1 Promoter Confers Fluconazole Resistance in Saccharomyces cerevisiae

    OpenAIRE

    Kontoyiannis, Dimitrios P.; Sagar, Namita; Hirschi, Kendal D.

    1999-01-01

    The contribution of the dosage of target enzyme P-450 14α-demethylase (14αDM) to fluconazole resistance in both Candida albicans and Saccharomyces cerevisiae remains unclear. Here, we show that overexpression of Saccharomyces P-450 14αDM in S. cerevisiae, under the control of the regulatable promoter GAL1, results in azole resistance.

  1. Growth-rate dependency of de novo resveratrol production in chemostat cultures of an engineered Saccharomyces cerevisiae strain

    NARCIS (Netherlands)

    Vos, T.; De la Torre Cortes, P.; Van Gulik, W.M.; Pronk, J.T.; Daran-Lapujade, P.A.S.

    2015-01-01

    Introduction: Saccharomyces cerevisiae has become a popular host for production of non-native compounds. The metabolic pathways involved generally require a net input of energy. To maximize the ATP yield on sugar in S. cerevisiae, industrial cultivation is typically performed in aerobic, sugar-limit

  2. Regulation of Lactobacillus plantarum contamination on the carbohydrate and energy related metabolisms of Saccharomyces cerevisiae during bioethanol fermentation.

    Science.gov (United States)

    Dong, Shi-Jun; Lin, Xiang-Hua; Li, Hao

    2015-11-01

    During the industrial bioethanol fermentation, Saccharomyces cerevisiae cells are often stressed by bacterial contaminants, especially lactic acid bacteria. Generally, lactic acid bacteria contamination can inhibit S. cerevisiae cell growth through secreting lactic acid and competing with yeast cells for micronutrients and living space. However, whether are there still any other influences of lactic acid bacteria on yeast or not? In this study, Lactobacillus plantarum ATCC 8014 was co-cultivated with S. cerevisiae S288c to mimic the L. plantarum contamination in industrial bioethanol fermentation. The contaminative L. plantarum-associated expression changes of genes involved in carbohydrate and energy related metabolisms in S. cerevisiae cells were determined by quantitative real-time polymerase chain reaction to evaluate the influence of L. plantarum on carbon source utilization and energy related metabolism in yeast cells during bioethanol fermentation. Contaminative L. plantarum influenced the expression of most of genes which are responsible for encoding key enzymes involved in glucose related metabolisms in S. cerevisiae. Specific for, contaminated L. plantarum inhibited EMP pathway but promoted TCA cycle, glyoxylate cycle, HMP, glycerol synthesis pathway, and redox pathway in S. cerevisiae cells. In the presence of L. plantarum, the carbon flux in S. cerevisiae cells was redistributed from fermentation to respiratory and more reducing power was produced to deal with the excess NADH. Moreover, L. plantarum contamination might confer higher ethanol tolerance to yeast cells through promoting accumulation of glycerol. These results also highlighted our knowledge about relationship between contaminative lactic acid bacteria and S. cerevisiae during bioethanol fermentation.

  3. Integrated phospholipidomics and transcriptomics analysis of Saccharomyces cerevisiae with enhanced tolerance to a mixture of acetic acid, furfural, and phenol

    Science.gov (United States)

    A mixture of acetic acid, furfural and phenol (AFP), three representative lignocellulose derived inhibitors, significantly inhibited the growth and bioethanol production of Saccharomyces cerevisiae. In order to uncover mechanisms behind the enhanced tolerance of an inhibitor-tolerant S.cerevisiae s...

  4. High-level production of beta-carotene in Saccharomyces cerevisiae by successive transformation with carotenogenic genes from Xanthophyllomyces dendrorhous

    NARCIS (Netherlands)

    Verwaal, R.; Wang, J.; Meijnen, J.P.; Visser, H.; Sandmann, G.; Berg, van den J.A.; Ooyen, van A.J.J.

    2007-01-01

    To determine whether Saccharomyces cerevisiae can serve as a host for efficient carotenoid and especially ß-carotene production, carotenogenic genes from the carotenoid-producing yeast Xanthophyllomyces dendrorhous were introduced and overexpressed in S. cerevisiae. Because overexpression of these g

  5. Crescimento bacteriano em perfluorocarbonos líquidos: estudo "in vitro" Bacterial growth in perfluorocarbon liquids: an in vitro study

    Directory of Open Access Journals (Sweden)

    Leciana Rorato Chiconelli Vanzo

    2001-08-01

    Full Text Available Objetivo: Verificar o crescimento de P. aeruginosa e S. aureus em perfluoroctano líquido (PFO. Métodos: Utilizaram-se três meios de cultura: PFO, caldo de digestão de soja e caseína e solução salina a 0,9%. Dividiram-se 5 ml de PFO em frascos contendo 1 ml cada. Nos frascos 1 e 2 inoculou-se 1 colônia inteira de P. aeruginosa e nos recipientes 3 e 4 a mesma quantidade de S. aureus. O frasco 5 serviu como controle sem sofrer contaminação. Inoculou-se também 1 colônia de cada bactéria em 1 ml dos demais meios de cultura. As soluções foram mantidas em incubadora a 37ºC por 10 dias. Em câmara de fluxo laminar realizou-se o repique utilizando-se alça calibrada de 1:1000 no tempo zero, 72 h, 168 h e 240 h após contaminação. Verificou-se o crescimento bacteriano por meio da contagem de colônias em placas de agar sangue 24 h após cada repique. Resultados: Houve crescimento de P. aeruginosa e S. aureus no tempo zero em todos os meios, confirmando a inoculação bacteriana. Nas horas seguintes o crescimento não mais foi observado em PFO. Ambas as bactérias desenvolveram-se abundantemente nos demais meios de cultura em todos os tempos. No frasco controle não houve crescimento bacteriano. Conclusão: Os resultados demonstram que o PFO não representa meio favorável para o crescimento bacteriano.Purpose: To determine the growth of P. aeruginosa and S. aureus in liquid perfluoroctane (PFO. Methods: Three culture media were used: PFO, soy and casein digestion broth and 0.9% saline solution. Five ml PFO were distributed to 1 ml flasks. Flasks 1 and 2 were inoculated with 1 entire colony of P. aeruginosa and flasks 3 and 4 were inoculated with the same amount of S. aureus. Flask 5 served as control without any contamination. One colony of each bacterium was also inoculated in 1 ml of the remaining culture media. All solutions were kept in an incubator at 37º C for 10 days. The cultures were replated under a laminar flow hood using a

  6. The golden root, Rhodiola rosea, prolongs lifespan but decreases oxidative stress resistance in yeast Saccharomyces cerevisiae.

    Science.gov (United States)

    Bayliak, Maria M; Lushchak, Volodymyr I

    2011-11-15

    The effect of aqueous extract from R. rosea root on lifespan and the activity of antioxidant enzymes in budding yeast Saccharomyces cerevisiae have been studied. The supplementation of the growth medium with R. rosea extract decreased survival of exponentially growing S. cerevisiae cells under H(2)O(2)-induced oxidative stress, but increased viability and reproduction success of yeast cells in stationary phase. The extract did not significantly affect catalase activity and decreased SOD activity in chronologically aged yeast population. These results suggest that R. rosea acts as a stressor for S. cerevisiae cells, what sensitizes yeast cells to oxidative stress at exponential phase, but induces adaptation in stationary phase cells demonstrating the positive effect on yeast survival without activation of major antioxidant enzymes.

  7. Increasing cocoa butter-like lipid production of Saccharomyces cerevisiae by expression of selected cocoa genes

    DEFF Research Database (Denmark)

    Wei, Yongjun; Gossing, Michael; Bergenholm, David

    2017-01-01

    Cocoa butter (CB) extracted from cocoa beans mainly consists of three different kinds of triacylglycerols (TAGs), 1,3-dipalmitoyl-2-oleoyl-glycerol (POP, C16:0-C18:1-C16:0), 1-palmitoyl-3-stearoyl-2-oleoyl-glycerol(POS,C16:0C18:1-C18:0) and 1,3-distearoyl-2-oleoyl-glycerol (SOS, C18:0-C18:1-C18....... TAG synthesis is mainly catalyzed by three enzymes: glycerol-3-phosphate acyltransferase (GPAT), lysophospholipid acyltransferase (LPAT) and diacylglycerol acyltransferase (DGAT). In order to produce CBL in S. cerevisiae, we selected six cocoa genes encoding GPAT, LPAT and DGAT potentially responsible...... for CB biosynthesis from the cocoa genome using a phylogenetic analysis approach. By expressing the selected cocoa genes in S. cerevisiae, we successfully increased total fatty acid production, TAG production and CBL production in some S. cerevisiae strains. The relative CBL content in three yeast...

  8. A new biological test of water toxicity-yeast Saccharomyces cerevisiae conductometric test.

    Science.gov (United States)

    Dolezalova, Jaroslava; Rumlova, Lubomira

    2014-11-01

    This new biological test of water toxicity is based on monitoring of specific conductivity changes of yeast Saccharomyces cerevisiae suspension as a result of yeast fermentation activity inhibition in toxic conditions. The test was verified on ten substances with various mechanisms of toxic effect and the results were compared with two standard toxicity tests based on Daphnia magna mobility inhibition (EN ISO 6341) and Vibrio fischeri bioluminescence inhibition (EN ISO 11348-2) and with the results of the S. cerevisiae lethal test (Rumlova and Dolezalova, 2012). The new biological test - S. cerevisiae conductometric test - is an express method developed primarily for field conditions. It is applicable in case of need of immediate information about water toxicity. Fast completion is an advantage of this test (time necessary for test completion is about 60min), the test is simple and the test organism - dried instant yeast - belongs among its biggest advantages because of its long-term storage life and broad availability.

  9. Novel strategy to improve vanillin tolerance and ethanol fermentation performances of Saccharomycere cerevisiae strains.

    Science.gov (United States)

    Zheng, Dao-Qiong; Jin, Xin-Na; Zhang, Ke; Fang, Ya-Hong; Wu, Xue-Chang

    2017-01-26

    The aim of this work was to develop a novel strategy for improving the vanillin tolerance and ethanol fermentation performances of Saccharomyces cerevisiae strains. Isogeneic diploid, triploid, and tetraploid S. cerevisiae strains were generated by genome duplication of haploid strain CEN.PK2-1C. Ploidy increments improved vanillin tolerance and diminished proliferation capability. Antimitotic drug methyl benzimidazol-2-ylcarbamate (MBC) was used to introduce chromosomal aberrations into the tetraploid S. cerevisiae strain. Interestingly, aneuploid mutants with DNA contents between triploid and tetraploid were more resistant to vanillin and showed faster ethanol fermentation rates than all euploid strains. The physiological characteristics of these mutants suggest that higher bioconversion capacities of vanillin and ergosterol contents might contribute to improved vanillin tolerance. This study demonstrates that genome duplication and MBC treatment is a powerful strategy to improve the vanillin tolerance of yeast strains.

  10. Development of a system for multicopy gene integration in Saccharomyces cerevisiae.

    Science.gov (United States)

    Semkiv, Marta V; Dmytruk, Kostyantyn V; Sibirny, Andriy A

    2016-01-01

    In this study we describe construction and evaluation of a vector for multicopy integration in yeast Saccharomyces cerevisiae. In this vector a modified selective marker and a reporter gene PHO8 (encoding alkaline phosphatase) were flanked with delta sequences of the Ty1 transposon. Modified by error-prone PCR version of selection marker kanMX4 was obtained from Escherichia coli clone with impaired geneticin (G418) resistance. The attenuation of kanMX4 gene provides an opportunity to select for explicitly multicopy integration of the module in S. cerevisiae using moderate (200 mg L(-1)) antibiotic concentrations. The developed system provided integration of 3-10 copies of the module in the genome of S. cerevisiae. High copy integration events were confirmed by qRT-PCR, Southern hybridization and reporter enzyme activity measurements.

  11. Parameter Optimization for Enhancement of Ethanol Yield by Atmospheric Pressure DBD-Treated Saccharomyces cerevisiae

    Science.gov (United States)

    Dong, Xiaoyu; Yuan, Yulian; Tang, Qian; Dou, Shaohua; Di, Lanbo; Zhang, Xiuling

    2014-01-01

    In this study, Saccharomyces cerevisiae (S. cerevisiae) was exposed to dielectric barrier discharge plasma (DBD) to improve its ethanol production capacity during fermentation. Response surface methodology (RSM) was used to optimize the discharge-associated parameters of DBD for the purpose of maximizing the ethanol yield achieved by DBD-treated S. cerevisiae. According to single factor experiments, a mathematical model was established using Box-Behnken central composite experiment design, with plasma exposure time, power supply voltage, and exposed-sample volume as impact factors and ethanol yield as the response. This was followed by response surface analysis. Optimal experimental parameters for plasma discharge-induced enhancement in ethanol yield were plasma exposure time of 1 min, power voltage of 26 V, and an exposed sample volume of 9 mL. Under these conditions, the resulting yield of ethanol was 0.48 g/g, representing an increase of 33% over control.

  12. Toxicity detection using lysosomal enzymes, glycoamylase and thioredoxin fused with fluorescent protein in Saccharomyces cerevisiae.

    Science.gov (United States)

    Nguyen, Ngoc-Tu; Shin, Hwa-Yoon; Kim, Yang-Hoon; Min, Jiho

    2015-11-20

    Saccharomyces cerevisiae is the simplest and a favorite eukaryotic system that contains lysosome and thus, is a suitable organism for monitoring some toxic effects in environmental pollution. In this study, S. cerevisiae was transformed with two recombinant plasmids. Sporulation-specific glycoamylase (SGA1), which was upregulated in response to arsenic, was fused with the blue fluorescent protein (BFP) for the construction of an oxidative stress-causing chemicals sensor. Additionally, thioredoxin (TRX2), a protein overexpressed exclusively under tetracycline's influence, fused with the cyan fluorescent protein (CFP) to create a detector for this kind of chemical. In summary, we developed two recombinant S. cerevisiae that facilitate the detection of both kinds of toxic chemicals, specifically visualized by different color indicators.

  13. Biological Treatment of Textile Effluent Using Candida zeylanoides and Saccharomyces cerevisiae Isolated from Soil

    Directory of Open Access Journals (Sweden)

    O. P. Abioye

    2014-01-01

    Full Text Available This study evaluates the efficacy of yeasts isolated from soil in the treatment of textile wastewater. Two yeast species were isolated from soil; they were identified as Candida zeylanoides and Saccharomyces cerevisiae. The yeasts were inoculated into flask containing effluent and incubated for 15 days. Saccharomyces cerevisiae showed the most significant treatment capacity with a 66% reduction in BOD; this was followed closely by Candida zeylanoides with 57.3% reduction in BOD and a consortium of the two species showed the least remediation potential of 36.9%. The use of Saccharomyces cerevisiae and Candida zeylanoides in treatment of textile wastewater will help to limit the adverse environmental and health implications associated with disposal of untreated effluent into water bodies.

  14. 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......-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...... global insight into how growth temperature affects differential physiological and transcriptional responses in laboratory and wine strains of S. cerevisiae....

  15. Occurrence and taxonomic characteristics of strains of Saccharomyces cerevisiae predominant in African indigenous fermented foods and beverages.

    Science.gov (United States)

    Jespersen, Lene

    2003-04-01

    Indigenous fermented foods and beverages play a major role in the diet of African people. The predominant yeast species seen is Saccharomyces cerevisiae, involved in basically three groups of indigenous fermented products: non-alcoholic starchy foods, alcoholic beverages and fermented milk. These products are to a great extent made by spontaneous fermentation and consequently S. cerevisiae often coexists with other microorganisms even though a microbiological succession usually takes place both between and within species. The functions of S. cerevisiae are mainly related to formation of alcohols and other aroma compounds, but stimulation of e.g. lactic acid bacteria, improvement of nutritional value, probiotic effects, inhibition of undesired microorganisms and production of tissue-degrading enzymes may also be observed. Several different isolates of S. cerevisiae have been shown to be involved in the fermentations and some of the isolates show pheno- and genotypic characteristics that deviate from those normally recognised for S. cerevisiae.

  16. CROMATOGRAFIA DE AFINIDADE COM CORANTE RED A versus TROCA IÔNICA-PERMEABILIDADE EM GEL: COMPARAÇÃO DA PRATICIDADE NA PURIFICAÇÃO DE ENTEROTOXINA ESTAFILOCÓCICA A

    Directory of Open Access Journals (Sweden)

    M. KAMOGAE

    1998-05-01

    Full Text Available O presente trabalho compara processos de purificação de enterotoxina estafilocócica A, utilizando cromatografia de afinidade com corante Red A em relação a troca iônica (SP - Sephadex C-25 - permeabilidade em gel (Sephadex G-75. Aplicou-se nas colunas o sobrenadante da cultura de Staphylococcus aureus 722 em caldo contendo 3% de triptona e suplementado com 1% de extrato de levedura, previamente concentradas com Amberlite CG-50. O processo capturou rapidamente a EEA, porém a proporção de 15 mg de resina para 150 mg de toxina causou saturação, recuperando apenas 10 a 30% de toxina do sobrenadante. A cromatografia de afinidade com Red A permitiu a recuperação de 60,87% de toxina aplicada em 76 horas, em relação a 114 horas requeridas para purificação utilizando coluna de troca iônica e permeabilidade em gel, com rendimento de 6,5%. O perfil eletroforético das amostras purificadas indicaram que, a toxina obtida da coluna Red A apresentou teor de pureza superior, na ordem de 90%, em relação a 60% atingida pelo método clássico.Culture supernatant of Staphylococcus aureus 722 in 3% triptone plus 1% yeast extract was used for EEA purification, proceeding comparison between dye ligand Red A affinity chromatography and classic chromatography. The capture of SEA with Amberlite CG-50 allowed rapid enterotoxin concentration from the culture supernatant. However, the ratio of 15 mg of the resin to a total of 150 mg of the toxin satured the resin, giving only 10 to 30% of SEA recuperation from the supernatant. The elution of concentrated material throught the Red A column resulted in a recovery of 60,87% of the toxin, and required 76 hours, indicating advantage on classic chromatography. Ion exchange column plus gel filtration recovered only 6,5 % of the SEA, and required 114 hours to conclude the procedure. The eletrophoresis of purified SEA indicated high grade of toxin obtained from Red A column, with 90 % of purity, compared to 60

  17. Changes and roles of membrane compositions in the adaptation of Saccharomyces cerevisiae to ethanol.

    Science.gov (United States)

    Wang, Yanfeng; Zhang, Shuxian; Liu, Huaqing; Zhang, Lei; Yi, Chenfeng; Li, Hao

    2015-12-01

    Bioethanol fermentation by Saccharomyces cerevisiae is often stressed by the accumulation of ethanol. Cell membrane is the first assaulting target of ethanol. Ethanol-adapted S. cerevisiae strains provide opportunity to shed light on membrane functions in the ethanol tolerance. This study aimed at clarifying the roles of cell membrane in the ethanol tolerance of S. cerevisiae through comparing membrane components between S. cerevisiae parental strain and ethanol-adapted strains. A directed evolutionary engineering was performed to obtain the ethanol-adapted S. cerevisiae strains. The parental, ethanol-adapted M5 and M10 strains were selected to be compared the percentage of viable cells after exposing to ethanol stress and cell membrane compositions (i.e., ergosterol, trehalose, and fatty acids). Compared with the parental strain, M5 or M10 strain had higher survival rate in the presence of 10% v/v ethanol. Compared with that in the parental strain, contents of trehalose, ergosterol, and fatty acids increased about 15.7, 12.1, and 29.3%, respectively, in M5 strain, and about 47.5, 107.8, and 61.5%, respectively, in M10 strain. Moreover, expression differences of genes involved in fatty acids metabolisms among the parental, M5 and M10 strains were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR), and results demonstrated that M5 or M10 strain had higher expression of ACC1 and OLE1 than the parental strain. These results indicated that although being exposed to step-wise increased ethanol, S. cerevisiae cells might remodel membrane components or structure to adapt to the ethanol stress.

  18. Nanofiltration concentration of extracellular glutathione produced by engineered Saccharomyces cerevisiae.

    Science.gov (United States)

    Sasaki, Kengo; Hara, Kiyotaka Y; Kawaguchi, Hideo; Sazuka, Takashi; Ogino, Chiaki; Kondo, Akihiko

    2016-01-01

    This study aimed to optimize extracellular glutathione production by a Saccharomyces cerevisiae engineered strain and to concentrate the extracellular glutathione by membrane separation processes, including ultrafiltration (UF) and nanofiltration (NF). Synthetic defined (SD) medium containing 20 g L(-1) glucose was fermented for 48 h; the fermentation liquid was passed through an UF membrane to remove macromolecules. Glutathione in this permeate was concentrated for 48 h to 545.1 ± 33.6 mg L(-1) using the NF membrane; this was a significantly higher concentration than that obtained with yeast extract peptone dextrose (YPD) medium following 96 h NF concentration (217.9 ± 57.4 mg L(-1)). This higher glutathione concentration results from lower cellular growth in SD medium (final OD600 = 6.9 ± 0.1) than in YPD medium (final OD600 = 11.0 ± 0.6) and thus higher production of extracellular glutathione (16.0 ± 1.3 compared to 9.2 ± 2.1 mg L(-1) in YPD medium, respectively). Similar fermentation and membrane processing of sweet sorghum juice containing 20 g L(-1) total sugars provided 240.3 ± 60.6 mg L(-1) glutathione. Increased extracellular production of glutathione by this engineered strain in SD medium and subsequent UF permeation and NF concentration in shortend time may help realize industrial recovery of extracellular glutathione.

  19. Interaction between lanthanide ions and Saccharomyces cerevisiae cells.

    Science.gov (United States)

    Ene, Cristian D; Ruta, Lavinia L; Nicolau, Ioana; Popa, Claudia V; Iordache, Virgil; Neagoe, Aurora D; Farcasanu, Ileana C

    2015-10-01

    Lanthanides are a group of non-essential elements with important imaging and therapeutic applications. Although trivalent lanthanide ions (Ln³⁺) are used as potent blockers of Ca²⁺ channels, the systematic studies correlating Ln³⁺ accumulation and toxicity to Ca²⁺ channel blocking activity are scarce. In this study, we made use of the eukaryotic model Saccharomyces cerevisiae to investigate the correlation between Ln³⁺ accumulation, their toxicity and their capacity to block the exogenous stress-induced Ca²⁺ influx into the cytosol. It was found that the Ln³⁺ blocked the Ca²⁺ entry into the yeast cells only when present at concentration high enough to allow rapid binding to cell surface. At lower concentrations, Ln³⁺ were taken up by the cell, but Ca²⁺ blockage was no longer achieved. At 1 mM concentration, all ions from the Ln³⁺ series could block Ca²⁺ entry into cytosol with the exception of La³⁺, and to a lesser extent, Pr³⁺ and Nd³⁺. The plasma membrane Ca²⁺-channel Cch1/Mid1 contributed to La³⁺ and Gd³⁺ entry into the cells, with a significant preference for La³⁺. The results open the possibility to obtain cells loaded with controlled amounts and ratios of Ln³⁺.

  20. Capturing of the monoterpene olefin limonene produced in Saccharomyces cerevisiae.

    Science.gov (United States)

    Jongedijk, Esmer; Cankar, Katarina; Ranzijn, Jorn; van der Krol, Sander; Bouwmeester, Harro; Beekwilder, Jules

    2015-01-01

    Monoterpene olefins such as limonene are plant compounds with applications as flavouring and fragrance agents, as solvents and potentially also in polymer and fuel chemistry. We engineered baker's yeast Saccharomyces cerevisiae to express a (-)-limonene synthase from Perilla frutescens and a (+)-limonene synthase from Citrus limon. Both proteins were expressed either with their native plastid targeting signal or in a truncated form in which the plastidial sorting signal was removed. The yeast host strain for expression was AE9 K197G, which expresses a mutant Erg20 enzyme. This enzyme catalyses the formation of geranyl diphosphate, which is the precursor for monoterpenes. Several methods were tested to capture limonene produced by the yeast. Extraction from the culture medium by pentane, or by the addition of CaCl2 followed by solid-phase micro-extraction, did not lead to detectable limonene, indicating that limonene is rapidly lost from the culture medium. Volatile terpenes such as limonene may also be trapped in a dodecane phase added to the medium during fermentation. This method resulted in recovery of 0.028 mg/l (+)-limonene and 0.060 mg/l (-)-limonene in strains using the truncated Citrus and Perilla synthases, respectively. Trapping the headspace during culture of the limonene synthase-expressing strains resulted in higher titres, at 0.12 mg/l (+)-limonene and 0.49 mg/l (-)-limonene. These results show that the volatile properties of the olefins produced require specific methods for efficient recovery of these molecules from biotechnological production systems.

  1. Rationally designed, heterologous S. cerevisiae transcripts expose novel expression determinants

    Science.gov (United States)

    Ben-Yehezkel, Tuval; Atar, Shimshi; Zur, Hadas; Diament, Alon; Goz, Eli; Marx, Tzipy; Cohen, Rafael; Dana, Alexandra; Feldman, Anna; Shapiro, Ehud; Tuller, Tamir

    2015-01-01

    Deducing generic causal relations between RNA transcript features and protein expression profiles from endogenous gene expression data remains a major unsolved problem in biology. The analysis of gene expression from heterologous genes contributes significantly to solving this problem, but has been heavily biased toward the study of the effect of 5′ transcript regions and to prokaryotes. Here, we employ a synthetic biology driven approach that systematically differentiates the effect of different regions of the transcript on gene expression up to 240 nucleotides into the ORF. This enabled us to discover new causal effects between features in previously unexplored regions of transcripts, and gene expression in natural regimes. We rationally designed, constructed, and analyzed 383 gene variants of the viral HRSVgp04 gene ORF, with multiple synonymous mutations at key positions along the transcript in the eukaryote S. cerevisiae. Our results show that a few silent mutations at the 5′UTR can have a dramatic effect of up to 15 fold change on protein levels, and that even synonymous mutations in positions more than 120 nucleotides downstream from the ORF 5′end can modulate protein levels up to 160%–300%. We demonstrate that the correlation between protein levels and folding energy increases with the significance of the level of selection of the latter in endogenous genes, reinforcing the notion that selection for folding strength in different parts of the ORF is related to translation regulation. Our measured protein abundance correlates notably(correlation up to r = 0.62 (p=0.0013)) with mean relative codon decoding times, based on ribosomal densities (Ribo-Seq) in endogenous genes, supporting the conjecture that translation elongation and adaptation to the tRNA pool can modify protein levels in a causal/direct manner. This report provides an improved understanding of transcript evolution, design principles of gene expression regulation, and suggests simple

  2. New Genes Involved in Osmotic Stress Tolerance in Saccharomyces cerevisiae

    Science.gov (United States)

    Gonzalez, Ramon; Morales, Pilar; Tronchoni, Jordi; Cordero-Bueso, Gustavo; Vaudano, Enrico; Quirós, Manuel; Novo, Maite; Torres-Pérez, Rafael; Valero, Eva

    2016-01-01

    Adaptation to changes in osmolarity is fundamental for the survival of living cells, and has implications in food and industrial biotechnology. It has been extensively studied in the yeast Saccharomyces cerevisiae, where the Hog1 stress activated protein kinase was discovered about 20 years ago. Hog1 is the core of the intracellular signaling pathway that governs the adaptive response to osmotic stress in this species. The main endpoint of this program is synthesis and intracellular retention of glycerol, as a compatible osmolyte. Despite many details of the signaling pathways and yeast responses to osmotic challenges have already been described, genome-wide approaches are contributing to refine our knowledge of yeast adaptation to hypertonic media. In this work, we used a quantitative fitness analysis approach in order to deepen our understanding of the interplay between yeast cells and the osmotic environment. Genetic requirements for proper growth under osmotic stress showed both common and specific features when hypertonic conditions were induced by either glucose or sorbitol. Tolerance to high-glucose content requires mitochondrial function, while defective protein targeting to peroxisome, GID-complex function (involved in negative regulation of gluconeogenesis), or chromatin dynamics, result in poor survival to sorbitol-induced osmotic stress. On the other side, the competitive disadvantage of yeast strains defective in the endomembrane system is relieved by hypertonic conditions. This finding points to the Golgi-endosome system as one of the main cell components negatively affected by hyperosmolarity. Most of the biological processes highlighted in this analysis had not been previously related to osmotic stress but are probably relevant in an ecological and evolutionary context. PMID:27733850

  3. Mathematical model of GAL regulon dynamics in Saccharomyces cerevisiae.

    Science.gov (United States)

    Apostu, Raluca; Mackey, Michael C

    2012-01-21

    Genetic switches are prevalent in nature and provide cells with a strategy to adapt to changing environments. The GAL switch is an intriguing example which is not understood in all detail. The GAL switch allows organisms to metabolize galactose, and controls whether the machinery responsible for the galactose metabolism is turned on or off. Currently, it is not known exactly how the galactose signal is sensed by the transcriptional machinery. Here we utilize quantitative tools to understand the S. cerevisiae cell response to galactose challenge, and to analyze the plausible molecular mechanisms underlying its operation. We work at a population level to develop a dynamic model based on the interplay of the key regulatory proteins Gal4p, Gal80p, and Gal3p. To our knowledge, the model presented here is the first to reproduce qualitatively the bistable network behavior found experimentally. Given the current understanding of the GAL circuit induction (Wightman et al., 2008; Jiang et al., 2009), we propose that the most likely in vivo mechanism leading to the transcriptional activation of the GAL genes is the physical interaction between galactose-activated Gal3p and Gal80p, with the complex Gal3p-Gal80p remaining bound at the GAL promoters. Our mathematical model is in agreement with the flow cytometry profiles of wild type, gal3Δ and gal80Δ mutant strains from Acar et al. (2005), and involves a fraction of actively transcribing cells with the same qualitative features as in the data set collected by Acar et al. (2010). Furthermore, the computational modeling provides an explanation for the contradictory results obtained by independent laboratories when tackling experimentally the issue of binary versus graded response to galactose induction.

  4. Ethanol production from carob extract by using Saccharomyces cerevisiae.

    Science.gov (United States)

    Turhan, Irfan; Bialka, Katherine L; Demirci, Ali; Karhan, Mustafa

    2010-07-01

    Carob has been widely grown in the Mediterranean region for a long time. It has been regarded as only a forest tree and has been neglected for other economical benefits. However, in recent years, this fruit has gained attention for several applications. As petroleum has become depleted, renewable energy production has started to gain attention all over the world; including the production of ethanol from underutilized agricultural products such as carob. In this project, the optimum extraction conditions were determined for the carob fruit by using the response surface design method. The obtained extract was utilized for production of ethanol by using suspended Saccharomyces cerevisiae fermentation. The effect of various fermentation parameters such as pH, media content and inoculum size were evaluated for ethanol fermentation in carob extract. Also, in order to determine economically appropriate nitrogen sources, four different nitrogen sources were evaluated. The optimum extraction condition for carob extract was determined to be 80 degrees C, 2h in 1:4 dilution rate (fruit: water ratio) according to the result of response surface analysis (115.3g/L). When the fermentation with pH at 5.5 was applied, the final ethanol concentration and production rates were 42.6g/L and 3.37 g/L/h, respectively, which were higher than using an uncontrolled pH. Among inoculum sizes of 1%, 3%, and 5%, 3% was determined as the best inoculum size. The maximum production rate and final ethanol concentration were 3.48 g/L/h and 44.51%, respectively, with an alternative nitrogen source of meat-bone meal. Overall, this study suggested that carob extract can be utilized for production of ethanol in order to meet the demands of renewable energy.

  5. Bioconversion of lactose/whey to fructose diphosphate with recombinant Saccharomyces cerevisiae cells

    Energy Technology Data Exchange (ETDEWEB)

    Compagno, C.; Tura, A.; Ranzi, B.M.; Martegani, E. (Univ. di Milano (Italy))

    1993-07-01

    Genetically engineered Saccharomyces cerevisiae strains that express Escherichia coli [beta]-galactosidase gene are able to bioconvert lactose or whey into fructose-1,6-diphosphate (FDP). High FDP yields from whey were obtained with an appropriate ratio between cell concentration and inorganic phosphate. The biomass of transformed cells can be obtained from different carbon sources, according to the expression vector bearing the lacZ gene. The authors showed that whey can be used as the carbon source for S. cerevisiae growth and as the substrate for bioconversion to fructose diphosphate.

  6. Expression of an Aspergillus niger Phytase Gene (phyA) in Saccharomyces cerevisiae

    OpenAIRE

    Han, Yanming; Wilson, David B.; Lei, Xin Gen

    1999-01-01

    Phytase improves the bioavailability of phytate phosphorus in plant foods to humans and animals and reduces phosphorus pollution of animal waste. Our objectives were to express an Aspergillus niger phytase gene (phyA) in Saccharomyces cerevisiae and to determine the effects of glycosylation on the phytase’s activity and thermostability. A 1.4-kb DNA fragment containing the coding region of the phyA gene was inserted into the expression vector pYES2 and was expressed in S. cerevisiae as an act...

  7. Glutatation Transferasas de clase Omega en Saccharomyces cerevisiae: Estudio Bioquímico y Funcional

    OpenAIRE

    Barreto Parra, Lina Patricia

    2007-01-01

    Saccharomyces cerevisiae posseeix dues glutatió transferases (GST) anomenades Gtt1i Gtt2, amb capacitat de conjugar una molècula de glutatió amb el substrat estàndarCDNB. Aquests dos enzims no són clasificables dins de les classes convencionalsdescrites en base a l'estructura de les GST d'eucariotes superiors, encara que guardencerta similitud estructural amb els membres de la classe Zeta. En aquesta memòria esdescriu la caracterització de tres GST de classe Omega en S. cerevisiae anomenadesG...

  8. 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

    1995-12-31

    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.)

  9. [Construction and fermentation control of reductive TCA pathway for malic acid production in Saccharomyces cerevisiae].

    Science.gov (United States)

    Yan, Daojiang; Wang, Caixia; Zhou, Jiemin; Liu, Yilan; Yang, Maohua; Xing, Jianmin

    2013-10-01

    Malic acid is widely used in food, and chemical industries. Through overexpressing pyruvate carboxylase and malate dehydrogenase in pdc1-deficient Saccharomyces cerevisiae, malic acid was successfully produced through the reductive TCA pathway. No malic acid was detected in wild type Saccharomyces cerevisiae, however, 45 mmol/L malic acid was produced in engineered strain, and the concentration of byproduct ethanol also reduced by 18%. The production of malic acid enhanced 6% by increasing the concentration of Ca2+. In addition, the final concentration reached 52.5 mmol/L malic acid by addition of biotin. The increasing is almost 16% higher than that of the original strain.

  10. Phytochelatins are synthesized by two vacuolar serine carboxypeptidases in Saccharomyces cerevisiae.

    Science.gov (United States)

    Wünschmann, Jana; Beck, Andreas; Meyer, Laurent; Letzel, Thomas; Grill, Erwin; Lendzian, Klaus J

    2007-04-17

    Phytochelatins (PCs) are cysteine-rich peptides that chelate heavy metal ions, thereby mediating heavy metal tolerance in plants, fission yeast, and Caenorhabditis elegans. They are synthesized from glutathione by PC synthase, a specific dipeptidyltransferase. While Saccharomyces cerevisiae synthesizes PCs upon exposure to heavy metal ions, the S. cerevisiae genome does not encode a PC synthase homologue. How PCs are synthesized in yeast is unclear. This study shows that the vacuolar serine carboxypeptidases CPY and CPC are responsible for PC synthesis in yeast. The finding of a PCS-like activity of these enzymes in vivo discloses another route for PC biosynthesis in eukaryotes.

  11. Potential extra-ribosomal functions of ribosomal proteins in Saccharomyces cerevisiae.

    Science.gov (United States)

    Lu, Hui; Zhu, Yi-Fei; Xiong, Juan; Wang, Rong; Jia, Zhengping

    2015-08-01

    Ribosomal proteins (RPs), are essential components of the ribosomes, the molecular machines that turn mRNA blueprints into proteins, as they serve to stabilize the structure of the rRNA, thus improving protein biosynthesis. In addition, growing evidence suggests that RPs can function in other cellular roles. In the present review, we summarize several potential extra-ribosomal functions of RPs in ribosomal biogenesis, transcription activity, translation process, DNA repair, replicative life span, adhesive growth, and morphological transformation in Saccharomyces cerevisiae. However, the future in-depth studies are needed to identify these novel secondary functions of RPs in S. cerevisiae.

  12. 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......, translation initiation, translation elongation, translation termination, translation elongation, and mRNA decay. Considering these information from the mechanisms of transcription and translation, we will include this stoichiometric reactions into the genome scale model for S. Cerevisiae to obtain the first...

  13. The conserved HDAC Rpd3 drives transcriptional quiescence in S. cerevisiae

    Directory of Open Access Journals (Sweden)

    Jeffrey N. McKnight

    2015-12-01

    Full Text Available Quiescence is a ubiquitous cell cycle stage conserved from microbes through humans and is essential to normal cellular function and response to changing environmental conditions. We recently reported a massive repressive event associated with quiescence in Saccharomyces cerevisiae, where Rpd3 establishes repressive chromatin structure that drives transcriptional shutoff [6]. Here, we describe in detail the experimental procedures, data collection, and data analysis related to our characterization of transcriptional quiescence in budding yeast (GEO: GSE67151. Our results provide a bona fide molecular event driven by widespread changes in chromatin structure through action of Rpd3 that distinguishes quiescence as a unique cell cycle stage in S. cerevisiae.

  14. Effects of proteinase A on cultivation and viability characteristics of industrial Saccharomyces cerevisiae WZ65

    Institute of Scientific and Technical Information of China (English)

    Hong-bo ZHANG; Hai-feng ZHANG; Qi-he CHEN; Hui RUAN; Ming-liang FU; Guo-qing HE

    2009-01-01

    Proteinase A (PrA), encoded by PEP4 gene, is a key enzyme in the vacuoles of Saccharomyces cerevisiae. We characterized the effects of PrA on cell growth and glucose metabolism in the industrial S. cerevisiae WZ65. It was observed that the lag phase of cell growth of partial PEP4 gene deletion mutant (36 h) and PrA-negative mutant (48 h) was significantly ex-tended, compared with the wild type strain (24 h) (P<0.05), but PrA had no effect on glucose metabolism either under shaking or steady state cultivations. The logistic model was chosen to evaluate the effect of PrA on S. cerevisiae cell growth, and PrA was found to promote cell growth against insufficient oxygen condition in steady state cultivation, but had no effect in shaking culti-vation. The effects of glucose starvation on cell growth of partial PEP4 gene deletion strain and PrA-negative mutant were also evaluated. The results show that PrA partial deficiency increased the adaption ofS. cerevisiae to unfavorable nutrient environment, but had no effect on glucose metabolism under the stress of low glucose. During heat shock test, at 60 ℃ the reduced cell viability rate (RCVR) was 10% for the wild type S. cerevisiae and 90% for both mutant strains (P<0.01), suggesting that PrA was a negative factor for S. cerevisiae cells to survive under heat shock. As temperatures rose from 60 ℃ to 70 ℃, the wild type S. cerevisiae had significantly lower relative glucose consumption rate (RGCR) (61.0% and 80.0%) than the partial mutant (78.0% and 98.5%) and the complete mutant (80.0% and 98.0%) (P<0.05), suggesting that, in coping with heat shock, cells of the PrA mutants increased their glucose consumption to survive. The present study may provide meaningful information for brewing industry; however, the role of PrA in industrial S. cerevisiae physiology is complex and needs to be further investigated.

  15. The RFC2 gene encoding a subunit of replication factor C of Saccharomyces cerevisiae.

    OpenAIRE

    Noskov, V; Maki, S.; Kawasaki, Y.; Leem, S H; Ono, B; Araki, H; Pavlov, Y; Sugino, A

    1994-01-01

    Replication Factor C (RF-C) of Saccharomyces cerevisiae is a complex that consists of several different polypeptides ranging from 120- to 37 kDa (Yoder and Burgers, 1991; Fien and Stillman, 1992), similar to human RF-C. We have isolated a gene, RFC2, that appears to be a component of the yeast RF-C. The RFC2 gene is located on chromosome X of S. cerevisiae and is essential for cell growth. Disruption of the RFC2 gene led to a dumbbell-shaped terminal morphology, common to mutants having a def...

  16. Two distinct DNA ligase activities in mitotic extracts of the yeast Saccharomyces cerevisiae.

    OpenAIRE

    Ramos, W; Tappe, N; Talamantez, J; Friedberg, E C; Tomkinson, A E

    1997-01-01

    Four biochemically distinct DNA ligases have been identified in mammalian cells. One of these enzymes, DNA ligase I, is functionally homologous to the DNA ligase encoded by the Saccharomyces cerevisiae CDC9 gene. Cdc9 DNA ligase has been assumed to be the only species of DNA ligase in this organism. In the present study we have identified a second DNA ligase activity in mitotic extracts of S. cerevisiae with chromatographic properties different from Cdc9 DNA ligase, which is the major DNA joi...

  17. Rad52 multimerization is important for its nuclear localization in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Plate, Iben; Albertsen, Line; Lisby, Michael

    2008-01-01

    Rad52 is essential for all homologous recombination and DNA double strand break repair events in Saccharomyces cerevisiae. This protein is multifunctional and contains several domains that allow it to interact with DNA as well as with different repair proteins. However, it has been unclear how Rad......52 enters the nucleus. In the present study, we have used a combination of mutagenesis and sequence analysis to show that Rad52 from S. cerevisiae contains a single functional pat7 type NLS essential for its nuclear localization. The region containing the NLS seems only to be involved in nuclear...

  18. Engineering of carbon catabolite repression in recombinant xylose fermenting Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Roca, Christophe Francois Aime; Haack, Martin Brian; Olsson, Lisbeth

    2004-01-01

    Two xylose-fermenting glucose-derepressed Saccharomyces cerevisiae strains were constructed in order to investigate the influence of carbon catabolite repression on xylose metabolism. S. cerevisiae CPB.CR2 (Deltamig1, XYL1, XYL2, XKS1) and CPB.MBH2 (Deltamig1, Deltamig2, XYL1, XYL2, XKS1) were...... of CPB.CR2, where the cells are assumed to grow under non-repressive conditions as they sense almost no glucose, invertase activity was lower during growth on xylose and glucose than on glucose only. The 3-fold reduction in invertase activity could only be attributed to the presence of xylose, suggesting...

  19. Effect of Temperature on the Prevalence of Saccharomyces Non cerevisiae Species against a S. cerevisiae Wine Strain in Wine Fermentation: Competition, Physiological Fitness, and Influence in Final Wine Composition

    Science.gov (United States)

    Alonso-del-Real, Javier; Lairón-Peris, María; Barrio, Eladio; Querol, Amparo

    2017-01-01

    Saccharomyces cerevisiae is the main microorganism responsible for the fermentation of wine. Nevertheless, in the last years wineries are facing new challenges due to current market demands and climate change effects on the wine quality. New yeast starters formed by non-conventional Saccharomyces species (such as S. uvarum or S. kudriavzevii) or their hybrids (S. cerevisiae x S. uvarum and S. cerevisiae x S. kudriavzevii) can contribute to solve some of these challenges. They exhibit good fermentative capabilities at low temperatures, producing wines with lower alcohol and higher glycerol amounts. However, S. cerevisiae can competitively displace other yeast species from wine fermentations, therefore the use of these new starters requires an analysis of their behavior during competition with S. cerevisiae during wine fermentation. In the present study we analyzed the survival capacity of non-cerevisiae strains in competition with S. cerevisiae during fermentation of synthetic wine must at different temperatures. First, we developed a new method, based on QPCR, to quantify the proportion of different Saccharomyces yeasts in mixed cultures. This method was used to assess the effect of competition on the growth fitness. In addition, fermentation kinetics parameters and final wine compositions were also analyzed. We observed that some cryotolerant Saccharomyces yeasts, particularly S. uvarum, seriously compromised S. cerevisiae fitness during competences at lower temperatures, which explains why S. uvarum can replace S. cerevisiae during wine fermentations in European regions with oceanic and continental climates. From an enological point of view, mixed co-cultures between S. cerevisiae and S. paradoxus or S. eubayanus, deteriorated fermentation parameters and the final product composition compared to single S. cerevisiae inoculation. However, in co-inoculated synthetic must in which S. kudriavzevii or S. uvarum coexisted with S. cerevisiae, there were fermentation

  20. Effect of Temperature on the Prevalence of Saccharomyces Non cerevisiae Species against a S. cerevisiae Wine Strain in Wine Fermentation: Competition, Physiological Fitness, and Influence in Final Wine Composition.

    Science.gov (United States)

    Alonso-Del-Real, Javier; Lairón-Peris, María; Barrio, Eladio; Querol, Amparo

    2017-01-01

    Saccharomyces cerevisiae is the main microorganism responsible for the fermentation of wine. Nevertheless, in the last years wineries are facing new challenges due to current market demands and climate change effects on the wine quality. New yeast starters formed by non-conventional Saccharomyces species (such as S. uvarum or S. kudriavzevii) or their hybrids (S. cerevisiae x S. uvarum and S. cerevisiae x S. kudriavzevii) can contribute to solve some of these challenges. They exhibit good fermentative capabilities at low temperatures, producing wines with lower alcohol and higher glycerol amounts. However, S. cerevisiae can competitively displace other yeast species from wine fermentations, therefore the use of these new starters requires an analysis of their behavior during competition with S. cerevisiae during wine fermentation. In the present study we analyzed the survival capacity of non-cerevisiae strains in competition with S. cerevisiae during fermentation of synthetic wine must at different temperatures. First, we developed a new method, based on QPCR, to quantify the proportion of different Saccharomyces yeasts in mixed cultures. This method was used to assess the effect of competition on the growth fitness. In addition, fermentation kinetics parameters and final wine compositions were also analyzed. We observed that some cryotolerant Saccharomyces yeasts, particularly S. uvarum, seriously compromised S. cerevisiae fitness during competences at lower temperatures, which explains why S. uvarum can replace S. cerevisiae during wine fermentations in European regions with oceanic and continental climates. From an enological point of view, mixed co-cultures between S. cerevisiae and S. paradoxus or S. eubayanus, deteriorated fermentation parameters and the final product composition compared to single S. cerevisiae inoculation. However, in co-inoculated synthetic must in which S. kudriavzevii or S. uvarum coexisted with S. cerevisiae, there were fermentation

  1. Emergency Medical Service (EMS) Stations

    Data.gov (United States)

    Kansas Data Access and Support Center — EMS Locations in Kansas The EMS stations dataset consists of any location where emergency medical services (EMS) personnel are stationed or based out of, or where...

  2. Isolation and Characterization of a Lycopene ε-Cyclase Gene of <em>Chlorella em>(Chromochloris> <em>zofingiensis>. Regulation of the Carotenogenic Pathway by Nitrogen and Light

    Directory of Open Access Journals (Sweden)

    Maria Angeles Vargas

    2012-09-01

    Full Text Available The isolation and characterization of the lycopene ε-cyclase gene from the green microalga <em>Chlorella em>(Chromochloris> <em>zofingiensis> (<em>Czlcy-e> was performed. This gene is involved in the formation of the carotenoids α-carotene and lutein. <em>Czlcy-e> gene encoded a polypeptide of 654 amino acids. A single copy of <em>Czlcy-e> was found in <em>C. zofingiensisem>. Functional analysis by heterologous complementation in <em>Escherichia coliem> showed the ability of this protein to convert lycopene to δ-carotene. In addition, the regulation of the carotenogenic pathway by light and nitrogen was also studied in <em>C. zofingiensisem>. High irradiance stress did not increase mRNA levels of neither lycopene β<em>->cyclase gene (<em>lcy-b> nor lycopene ε-cyclase gene<em> em>(lcy-e> as compared with low irradiance conditions, whereas the transcript levels of <em>psy>, <em>pds>, <em>chyB> and <em>bkt> genes were enhanced, nevertheless triggering the synthesis of the secondary carotenoids astaxanthin, canthaxanthin and zeaxanthin and decreasing the levels of the primary carotenoids α-carotene, lutein, violaxanthin and β-carotene. Nitrogen starvation <em>per seem> enhanced mRNA levels of all genes considered, except <em>lcy-e and pdsem>, but did not trigger the synthesis of astaxanthin, canthaxanthin nor zeaxanthin. The combined effect of both high light and nitrogen starvation stresses enhanced significantly the accumulation of these carotenoids as well as the transcript levels of <em>bkt> gene, as compared with the effect of only high irradiance stress.

  3. Electrical stimulation of saccharomyces cerevisiae cultures Estimulação elétrica de células de Saccharomyces cerevisiae

    OpenAIRE

    Araújo,Ofelia Q.F.; Coelho, Maria Alice Z.; Margarit,Isabel C.P.; Vaz-Junior,Carlos A.; Maria Helena M. Rocha-Leão

    2004-01-01

    Modulation of cell endogenous membrane potential by an external electrical field influences the structure and function of membrane compartments, proteins and lipid bi-layer. In this work, the effects of applied potential on Saccharomyces cerevisiae growth were characterized through simple yet conclusive experiments. Cell growth time profile and cell division were investigated as macroscopic response to the electrical stimulation. Control experiments were conducted under identical conditions e...

  4. <em>Angiostrongylus vasorumem> in red foxes (<em>Vulpes vulpesem> and badgers (<em>Meles melesem> from Central and Northern Italy

    Directory of Open Access Journals (Sweden)

    Marta Magi

    2010-06-01

    Full Text Available Abstract During 2004-2005 and 2007-2008, 189 foxes (<em>Vulpes vulpesem> and 6 badgers (<em>Meles melesem> were collected in different areas of Central Northern Italy (Piedmont, Liguria and Tuscany and examined for <em>Angiostrongylus vasorumem> infection. The prevalence of the infection was significantly different in the areas considered, with the highest values in the district of Imperia (80%, Liguria and in Montezemolo (70%, southern Piedmont; the prevalence in Tuscany was 7%. One badger collected in the area of Imperia turned out to be infected, representing the first report of the parasite in this species in Italy. Further studies are needed to evaluate the role played by fox populations as reservoirs of infection and the probability of its spreading to domestic dogs.
    Riassunto <em>Angiostrongylus vasorumem> nella volpe (<em>Vulpes vulpesem> e nel tasso (<em>Meles melesem> in Italia centro-settentrionale. Nel 2004-2005 e 2007-2008, 189 volpi (<em>Vulpes vulpesem> e 6 tassi (<em>Meles melesem> provenienti da differenti aree dell'Italia settentrionale e centrale (Piemonte, Liguria Toscana, sono stati esaminati per la ricerca di <em>Angiostrongylus vasorumem>. La prevalenza del nematode è risultata significativamente diversa nelle varie zone, con valori elevati nelle zone di Imperia (80% e di Montezemolo (70%, provincia di Cuneo; la prevalenza in Toscana è risultata del 7%. Un tasso proveniente dall'area di Imperia è risultato positivo per A. vasorum; questa è la prima segnalazione del parassita in tale specie in Italia. Ulteriori studi sono necessari per valutare il potenziale della volpe come serbatoio e la possibilità di diffusione della parassitosi ai cani domestici.

    doi:10.4404/hystrix-20.2-4442

  5. <em>An entem>-Kaurane-Type Diterpene in <em>Croton antisyphiliticusem> Mart.

    Directory of Open Access Journals (Sweden)

    Ana Maria Pereira

    2012-07-01

    Full Text Available <em>Croton antisyphiliticus em>is a medicinal plant widely used in the treatment of microbial infections, especially those affecting the genital tract. Crude extract, fractions and pure compound isolated from roots of this species were investigated to validate their antimicrobial activity against <em>Escherichia coliem> and <em>Staphylococcus aureusem>. The compound <em>ent>-kaur-16-en-18-oic acid was isolated as a major component (0.7% of crude extract, and its MIC value determined against <em>S. aureusem> (ATCC 6538 was 250 μg/mL. This is the first phytochemical work on the species monitored with antimicrobial assay.

  6. Physiology of Saccharomyces cerevisiae during cell cycle oscillations.

    Science.gov (United States)

    Duboc, P; Marison, I; von Stockar, U

    1996-10-18

    Synchronized populations of Saccharomyces cerevisiae CBS 426 are characterized by autonomous oscillations of process variables. CO2 evolution rate, O2 uptake rate and heat production rate varied by a factor of 2 for a continuous culture grown at a dilution rate of 0.10 h-1. Elemental analysis showed that the carbon mass fraction of biomass did not change. Since the reactor is not at steady state, the elemental and energy balances were calculated on cumulated quantities, i.e. the integral of the reaction rates. It was possible to show that carbon, degree of reduction and energy balances matched. Application of simple mass balance principles for non-steady state systems indicated that oscillations were basically characterized by changes in biomass production rate. In addition, the amount of intermediates, e.g. ethanol or acetate, produced or consumed was negligible. Growth rate was low during the S-phase (0.075 h-1) and high during the G2, M and G1 phases (0.125 h-1) for a constant dilution rate of 0.10 h-1. However, nitrogen, ash, sulfur and potassium content showed systematic increases during the S-phase (bud initiation). Cell component analyses showed that changes in cellular fractions during oscillations (storage carbohydrate content decreased during the S-phase) were due to changes in production rates, particularly for protein and carbohydrates. Nevertheless, using the data evaluation techniques for dynamic systems presented here, it was shown that storage carbohydrates are not consumed during the S-phase. Only the synthesis rate of the different cell components changed depending on position in cell cycle. The growth process may be divided into two phenomena: the formation of new cells during mitosis with a low yield, and size increase of new born cells with high yield. Both kinetic and stoichiometric coefficients varied with the position in the oscillation: the results showed that biomass structure changed and that specific growth rate, as well as biomass yield

  7. "Ant" and "grasshopper" life-history strategies in Saccharomyces cerevisiae.

    Directory of Open Access Journals (Sweden)

    Aymé Spor

    Full Text Available From the evolutionary and ecological points of view, it is essential to distinguish between the genetic and environmental components of the variability of life-history traits and of their trade-offs. Among the factors affecting this variability, the resource uptake rate deserves particular attention, because it depends on both the environment and the genetic background of the individuals. In order to unravel the bases of the life-history strategies in yeast, we grew a collection of twelve strains of Saccharomyces cerevisiae from different industrial and geographical origins in three culture media differing for their glucose content. Using a population dynamics model to fit the change of population size over time, we estimated the intrinsic growth rate (r, the carrying capacity (K, the mean cell size and the glucose consumption rate per cell. The life-history traits, as well as the glucose consumption rate, displayed large genetic and plastic variability and genetic-by-environment interactions. Within each medium, growth rate and carrying capacity were not correlated, but a marked trade-off between these traits was observed over the media, with high K and low r in the glucose rich medium and low K and high r in the other media. The cell size was tightly negatively correlated to carrying capacity in all conditions. The resource consumption rate appeared to be a clear-cut determinant of both the carrying capacity and the cell size in all media, since it accounted for 37% to 84% of the variation of those traits. In a given medium, the strains that consume glucose at high rate have large cell size and low carrying capacity, while the strains that consume glucose at low rate have small cell size but high carrying capacity. These two contrasted behaviors may be metaphorically defined as "ant" and "grasshopper" strategies of resource utilization. Interestingly, a strain may be "ant" in one medium and "grasshopper" in another. These life

  8. Crystal structure of Saccharomyces cerevisiae 6-phosphogluconate dehydrogenase Gnd1

    Directory of Open Access Journals (Sweden)

    Zhou Cong-Zhao

    2007-06-01

    Full Text Available Abstract Background As the third enzyme of the pentose phosphate pathway, 6-phosphogluconate dehydrogenase (6PGDH is the main generator of cellular NADPH. Both thioredoxin reductase and glutathione reductase require NADPH as the electron donor to reduce oxidized thioredoxin or glutathione (GSSG. Since thioredoxin and GSH are important antioxidants, it is not surprising that 6PGDH plays a critical role in protecting cells from oxidative stress. Furthermore the activity of 6PGDH is associated with several human disorders including cancer and Alzheimer's disease. The 3D structural investigation would be very valuable in designing small molecules that target this enzyme for potential therapeutic applications. Results The crystal structure of 6-phosphogluconate dehydrogenase (6PGDH/Gnd1 from Saccharomyces cerevisiae has been determined at 2.37 Å resolution by molecular replacement. The overall structure of Gnd1 is a homodimer with three domains for each monomer, a Rossmann fold NADP+ binding domain, an all-α helical domain contributing the majority to hydrophobic interaction between the two subunits and a small C-terminal domain penetrating the other subunit. In addition, two citrate molecules occupied the 6PG binding pocket of each monomer. The intact Gnd1 had a Km of 50 ± 9 μM for 6-phosphogluconate and of 35 ± 6 μM for NADP+ at pH 7.5. But the truncated mutants without the C-terminal 35, 39 or 53 residues of Gnd1 completely lost their 6PGDH activity, despite remaining the homodimer in solution. Conclusion The overall tertiary structure of Gnd1 is similar to those of 6PGDH from other species. The substrate and coenzyme binding sites are well conserved, either from the primary sequence alignment, or from the 3D structural superposition. Enzymatic activity assays suggest a sequential mechanism of catalysis, which is in agreement with previous studies. The C-terminal domain of Gnd1 functions as a hook to further tighten the dimer, but it is not

  9. Multiplicação de Bacillus subtilis em vinhaça e viabilidade no controle da meloidoginose, em cana-de-açúcar Multiplication of Bacillus subtilis in vinasse and viability to control root-knot in sugarcane

    Directory of Open Access Journals (Sweden)

    Rodrigo B. Cardozo

    2011-12-01

    Full Text Available Objetivou-se, com este trabalho, avaliar o controle da meloidoginose e o crescimento da cana-de-açúcar, em função da aplicação de Bacillus subtilis ao solo após multiplicação em vinhaça. Bioensaios foram conduzidos em laboratório com avaliação do crescimento de B. subtilis em meio líquido com interesse na melhor composição de meio de cultura, a partir da vinhaça. No experimento em casa de vegetação foi utilizado solo coletado em área de cultivo de cana com histórico de alta infestação com Meloidogyne spp. No solo acondicionado em vasos efetuou-se o plantio da variedade de cana-de-açúcar RB 72454, cujos tratamentos foram: controle; vinhaça pura (50 m³ ha-1; Bacillus subtilis em suspensão aquosa (50 m³ ha-1; B. subtilis multiplicado na vinhaça para 50 m³ ha-1 e 100 m³ ha-1. A multiplicação de Bacillus subtilis em meio de cultura à base de vinhaça (25% foi significativamente superior em comparação com o meio de cultura caldo nutriente. A aplicação de B. subtilis em suspensão aquosa promoveu o crescimento e a redução da reprodução dos nematóides em cana-de-açúcar durante o experimento. A aplicação de B. subtilis multiplicado na vinhaça não proporcionou os benefícios de estímulo ao crescimento e controle da meloidoginose na cana-de-açúcar, encontrados com a aplicação apenas da bactéria no solo.This work aimed to evaluate the control of root-knot nematodes and sugarcane growth in function of Bacillus subtilis in soil after multiplication in vinasse. Laboratory tests were developed to define the best concentration of vinasse on the composition of culture medium to optimize the growth of B. subtilis. For the experiment in the greenhouse, soil collected in the area of sugarcane cultivation was used. The following treatments were established: control, vinasse (50 m³ ha-1, Bacillus subtilis in aqueous suspension (50 m³ ha-1; B. subtilis multiplied in vinasse (50 and 100 m³ ha-1. The

  10. Engineering of Saccharomyces cerevisiae for production of resveratrol and its derivatives

    DEFF Research Database (Denmark)

    Li, Mingji

    Resveratrol is a natural potent antioxidant with multiple beneficial effects on human health and is therefore used in medical, food, and cosmetic areas. In my PhD thesis I describe how I engineered yeast cell factory Saccharomyces cerevisiae for production of resveratrol by fermentation of cheap ...

  11. Engineering of Saccharomyces cerevisiae for Efficient Anaerobic Alcoholic Fermentation of L-Arabinose

    NARCIS (Netherlands)

    Wisselink, H.W.; Toirkens, M.J.; Del Rosario Franco Berriel, M.; Winkler, A.A.; Van Dijken, J.P.; Pronk, J.T.; Van Maris, A.J.A.

    2007-01-01

    For cost-effective and efficient ethanol production from lignocellulosic fractions of plant biomass, the conversion of not only major constituents, such as glucose and xylose, but also less predominant sugars, such as L-arabinose, is required. Wild-type strains of Saccharomyces cerevisiae, the organ

  12. Behavior of Lactobacillus plantarum and Saccharomyces cerevisiae in fresh and thermally processed orange juice.

    Science.gov (United States)

    Alwazeer, Duried; Cachon, Remy; Divies, Charles

    2002-10-01

    Lactobacillus plantarum and Saccharomyces cerevisiae are acid-tolerant microorganisms that are able to spoil citrus juices before and after pasteurization. The growth of these microorganisms in orange juice with and without pasteurization was investigated. Two samples of orange juice were inoculated with ca. 10(5) CFU/ml of each microorganism. Others were inoculated with ca. 10(7) CFU/ml of each microorganism and then thermally treated. L. plantarum populations were reduced by 2.5 and 6 and 2 log10 CFU/ml, respectively. Samples of heated and nonheated juice were incubated at 15 degrees C for 20 days. Injured populations of L. plantarum decreased by ca. 2 log10 CFU/ml during the first 70 h of storage, but those of S. cerevisiae did not decrease. The length of the lag phase after pasteurization increased 6.2-fold for L. plantarum and 1.9-fold for S. cerevisiae, and generation times increased by 41 and 86%, respectively. The results of this study demonstrate the differences in the capabilities of intact and injured cells of spoilage microorganisms to spoil citrus juice and the different thermal resistance levels of cells. While L. plantarum was more resistant to heat treatment than S. cerevisiae was, growth recovery after pasteurization was faster for the latter microorganism.

  13. Separate and Simultaneous enzymatic hydrolysis and fermentation of wheat hemicellulose with recombinant xylose utilizing Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Olsson, Lisbeth; Sørensen, H. R.; Dam, B. P;

    2006-01-01

    Fermentations with three different xylose-utilizing recombinant Saccharomyces cerevisiae strains (F12, CR4, and CB4) were performed using two different wheat hemicellulose substrates, unfermented starch free fibers, and an industrial ethanol fermentation residue, vinasse. With CR4 and F12...

  14. amdSYM, a new dominant recyclable marker cassette for Saccharomyces cerevisiae

    NARCIS (Netherlands)

    Solis-Escalante, D.; Kuijpers, N.G.A.; Bongaerts, N.; Bolat, I.; Bosman, L.; Pronk, J.T.; Daran, J.M.; Daran-Lapujade, P.A.S.

    2012-01-01

    Despite the large collection of selectable marker genes available for Saccharomyces cerevisiae, marker availability can still present a hurdle when dozens of genetic manipulations are required. Recyclable markers, counterselectable cassettes that can be removed from the targeted genome after use, ar

  15. Metabolic engineering of Saccharomyces cerevisiae for the overproduction of short branched-chain fatty acids.

    Science.gov (United States)

    Yu, Ai-Qun; Juwono, Nina Kurniasih Pratomo; Foo, Jee Loon; Leong, Susanna Su Jan; Chang, Matthew Wook

    2016-03-01

    Short branched-chain fatty acids (SBCFAs, C4-6) are versatile platform intermediates for the production of value-added products in the chemical industry. Currently, SBCFAs are mainly synthesized chemically, which can be costly and may cause environmental pollution. In order to develop an economical and environmentally friendly route for SBCFA production, we engineered Saccharomyces cerevisiae, a model eukaryotic microorganism of industrial significance, for the overproduction of SBCFAs. In particular, we employed a combinatorial metabolic engineering approach to optimize the native Ehrlich pathway in S. cerevisiae. First, chromosome-based combinatorial gene overexpression led to a 28.7-fold increase in the titer of SBCFAs. Second, deletion of key genes in competing pathways improved the production of SBCFAs to 387.4 mg/L, a 31.2-fold increase compared to the wild-type. Third, overexpression of the ATP-binding cassette (ABC) transporter PDR12 increased the secretion of SBCFAs. Taken together, we demonstrated that the combinatorial metabolic engineering approach used in this study effectively improved SBCFA biosynthesis in S. cerevisiae through the incorporation of a chromosome-based combinatorial gene overexpression strategy, elimination of genes in competitive pathways and overexpression of a native transporter. We envision that this strategy could also be applied to the production of other chemicals in S. cerevisiae and may be extended to other microbes for strain improvement.

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

    DEFF Research Database (Denmark)

    Borodina, Irina; Nielsen, Jens

    2014-01-01

    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...

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

    DEFF Research Database (Denmark)

    Regenberg, Birgitte; Grotkjaer, 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...

  18. Heterologous production of non-ribosomal peptide LLD-ACV in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Siewers, Verena; Chen, Xiao; Huang, Le

    2009-01-01

    -(l-α-aminoadipyl)–l-cysteinyl–d-valine (ACV) as a model NRP. The Penicillium chrysogenum gene pcbAB encoding ACV synthetase was expressed in S. cerevisiae from a high-copy plasmid together with phosphopantetheinyl transferase (PPTase) encoding genes from Aspergillus nidulans, P. chrysogenum and Bacillus subtilis, and in all the three cases...

  19. Evaluation of molecular typing techniques to assign genetic diversity among Saccharomyces cerevisiae strains

    NARCIS (Netherlands)

    Baleiras Couto, M.M.; Eijsma, B.; Hofstra, H.; Huis in 't Veld, J.H.J.; Vossen, J.M.B.M. van der

    1996-01-01

    Discrimination of strains within the species Saccharomyces cerevisiae was demonstrated by the use of four different techniques to type 15 strains isolated from spoiled wine and beer. Random amplified polymorphic DNA with specific oligonucleotides and PCR fingerprinting with the microsatellite oligon

  20. Bioprospecting and evolving alternative xylose and arabinose pathway enzymes for use in Saccharomyces cerevisiae.

    Science.gov (United States)

    Lee, Sun-Mi; Jellison, Taylor; Alper, Hal S

    2016-03-01

    Bioprospecting is an effective way to find novel enzymes from strains with desirable phenotypes. Such bioprospecting has enabled organisms such as Saccharomyces cerevisiae to utilize nonnative pentose sugars. Yet, the efficiency of this pentose catabolism (especially for the case of arabinose) remains suboptimal. Thus, further pathway optimization or identification of novel, optimal pathways is needed. Previously, we identified a novel set of xylan catabolic pathway enzymes from a superior pentose-utilizing strain of Ustilago bevomyces. These enzymes were used to successfully engineer a xylan-utilizing S. cerevisiae through a blended approach of bioprospecting and evolutionary engineering. Here, we expanded this approach to xylose and arabinose catabolic pathway engineering and demonstrated that bioprospected xylose and arabinose catabolic pathways from U. bevomyces offer alternative choices for enabling efficient pentose catabolism in S. cerevisiae. By introducing a novel set of xylose catabolic genes from U. bevomyces, growth rates were improved up to 85 % over a set of traditional Scheffersomyces stipitis pathway genes. In addition, we suggested an alternative arabinose catabolic pathway which, after directed evolution and pathway engineering, enabled S. cerevisiae to grow on arabinose as a sole carbon source in minimal medium with growth rates upwards of 0.05 h(-1). This pathway represents the most efficient growth of yeast on pure arabinose minimal medium. These pathways provide great starting points for further strain development and demonstrate the utility of bioprospecting from U. bevomyces.

  1. Xylan catabolism is improved by blending bioprospecting and metabolic pathway engineering in Saccharomyces cerevisiae.

    Science.gov (United States)

    Lee, Sun-Mi; Jellison, Taylor; Alper, Hal S

    2015-04-01

    Complete utilization of all available carbon sources in lignocellulosic biomass still remains a challenge in engineering Saccharomyces cerevisiae. Even with efficient heterologous xylose catabolic pathways, S. cerevisiae is unable to utilize xylose in lignocellulosic biomass unless xylan is depolymerized to xylose. Here we demonstrate that a blended bioprospecting approach along with pathway engineering and evolutionary engineering can be used to improve xylan catabolism in S. cerevisiae. Specifically, we perform whole genome sequencing-based bioprospecting of a strain with remarkable pentose catabolic potential that we isolated and named Ustilago bevomyces. The heterologous expression of xylan catabolic genes enabled S. cerevisiae to grow on xylan as a single carbon source in minimal medium. A combination of bioprospecting and metabolic pathway evolution demonstrated that the xylan catabolic pathway could be further improved. Ultimately, engineering efforts were able to achieve xylan conversion into ethanol of up to 0.22 g/L on minimal medium compositions with xylan. This pathway provides a novel starting point for improving lignocellulosic conversion by yeast.

  2. The origin recognition complex links replication, sister chromatid cohesion and transcriptional silencing in Saccharomyces cerevisiae

    NARCIS (Netherlands)

    Suter, Bernhard; Tong, Amy; Chang, Michael; Yu, Lisa; Brown, Grant W; Boone, Charles; Rine, Jasper

    2004-01-01

    Mutations in genes encoding the origin recognition complex (ORC) of Saccharomyces cerevisiae affect initiation of DNA replication and transcriptional repression at the silent mating-type loci. To explore the function of ORC in more detail, a screen for genetic interactions was undertaken using large

  3. Identification of novel knockout targets for improving terpenoids biosynthesis in Saccharomyces cerevisiae.

    Science.gov (United States)

    Sun, Zhiqiang; Meng, Hailin; Li, Jing; Wang, Jianfeng; Li, Qian; Wang, Yong; Zhang, Yansheng

    2014-01-01

    Many terpenoids have important pharmacological activity and commercial value; however, application of these terpenoids is often limited by problems associated with the production of sufficient amounts of these molecules. The use of Saccharomyces cerevisiae (S. cerevisiae) for the production of heterologous terpenoids has achieved some success. The objective of this study was to identify S. cerevisiae knockout targets for improving the synthesis of heterologous terpeniods. On the basis of computational analysis of the S. cerevisiae metabolic network, we identified the knockout sites with the potential to promote terpenoid production and the corresponding single mutant was constructed by molecular manipulations. The growth rates of these strains were measured and the results indicated that the gene deletion had no adverse effects. Using the expression of amorphadiene biosynthesis as a testing model, the gene deletion was assessed for its effect on the production of exogenous terpenoids. The results showed that the dysfunction of most genes led to increased production of amorphadiene. The yield of amorphadiene produced by most single mutants was 8-10-fold greater compared to the wild type, indicating that the knockout sites can be engineered to promote the synthesis of exogenous terpenoids.

  4. Sensitivity to Lovastatin of Saccharomyces cerevisiae Strains Deleted for Pleiotropic Drug Resistance (PDR) Genes

    DEFF Research Database (Denmark)

    Formenti, Luca Riccardo; Kielland-Brandt, Morten

    2011-01-01

    based on the use of statins. We investigated the susceptibility to lovastatin of S. cerevisiae strains deleted for PDR genes, responsible for exporting hydrophobic and amphi-philic drugs, such as lovastatin. Strains deleted for the genes tested, PDR1, PDR3, PDR5 and SNQ2, exhibited remarkably different...

  5. Implementation of communication-mediating domains for non-ribosomal peptide production in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Siewers, Verena; San-Bento, Rita; Nielsen, Jens

    2010-01-01

    Saccharomyces cerevisiae has in several cases been proven to be a suitable host for the production of natural products and was recently exploited for the production of non-ribosomal peptides. Synthesis of non-ribosomal peptides (NRPs) is mediated by NRP synthetases (NRPSs), modular enzymes, which...

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

    NARCIS (Netherlands)

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

    2014-01-01

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

  7. Genome-wide transcriptional response of a Saccharomyces cerevisiae strain with an altered redox metabolism

    DEFF Research Database (Denmark)

    Bro, Christoffer; Regenberg, Birgitte; Nielsen, Jens

    2004-01-01

    The genome-wide transcriptional response of a Saccharomyces cerevisiae strain deleted in GDH1 that encodes a NADP(+)-dependent glutamate dehydrogenase was compared to a wild-type strain under anaerobic steady-state conditions. The GDH1-deleted strain has a significantly reduced NADPH requirement...

  8. Production of 1,2-propanediol from glycerol in Saccharomyces cerevisiae.

    Science.gov (United States)

    Jung, Joon-Young; Yun, Hyun Shik; Lee, Jinwon; Oh, Min-Kyu

    2011-08-01

    Glycerol has become an attractive carbon source in the biotechnology industry owing to its low price and reduced state. However, glycerol is rarely used as a carbon source in Saccharomyces cerevisiae because of its low utilization rate. In this study, we used glycerol as a main carbon source in S. cerevisiae to produce 1,2-propanediol. Metabolically engineered S. cerevisiae strains with overexpression of glycerol dissimilation pathway genes, including glycerol kinase (GUT1), glycerol 3-phosphate dehydrogenase (GUT2), glycerol dehydrogenase (gdh), and a glycerol transporter gene (GUP1), showed increased glycerol utilization and growth rate. More significant improvement of glycerol utilization and growth rate was accomplished by introducing 1,2-propanediol pathway genes, mgs (methylglyoxal synthase) and gldA (glycerol dehydrogenase) from Escherichia coli. By engineering both glycerol dissimilation and 1,2-propanediol pathways, the glycerol utilization and growth rate were improved 141% and 77%, respectively, and a 2.19 g 1,2- propanediol/l titer was achieved in 1% (v/v) glycerolcontaining YEPD medium in engineered S. cerevisiae.

  9. Production of pyruvate from mannitol by mannitol-assimilating pyruvate decarboxylase-negative Saccharomyces cerevisiae.

    Science.gov (United States)

    Yoshida, Shiori; Tanaka, Hideki; Hirayama, Makoto; Murata, Kousaku; Kawai, Shigeyuki

    2015-01-01

    Mannitol is contained in brown macroalgae up to 33% (w/w, dry weight), and thus is a promising carbon source for white biotechnology. However, Saccharomyces cerevisiae, a key cell factory, is generally regarded to be unable to assimilate mannitol for growth. We have recently succeeded in producing S. cerevisiae that can assimilate mannitol through spontaneous mutations of Tup1-Cyc8, each of which constitutes a general corepressor complex. In this study, we demonstrate production of pyruvate from mannitol using this mannitol-assimilating S. cerevisiae through deletions of all 3 pyruvate decarboxylase genes. The resultant mannitol-assimilating pyruvate decarboxylase-negative strain produced 0.86 g/L pyruvate without use of acetate after cultivation for 4 days, with an overall yield of 0.77 g of pyruvate per g of mannitol (the theoretical yield was 79%). Although acetate was not needed for growth of this strain in mannitol-containing medium, addition of acetate had a significant beneficial effect on production of pyruvate. This is the first report of production of a valuable compound (other than ethanol) from mannitol using S. cerevisiae, and is an initial platform from which the productivity of pyruvate from mannitol can be improved.

  10. Polymorphism within the nuclear and 2 micron genomes of Saccharomyces cerevisiae.

    Science.gov (United States)

    Rank, G H; Casey, G P; Xiao, W; Pringle, A T

    1991-08-01

    Seven strains of bakers' yeast were obtained as a representative sample of the Spanish baking industry. The nuclear genome was monitored for polymorphism by transverse alternating field electrophoresis (TAFE) and restriction maps of 2 micron DNA were produced. All seven strains were uniquely different when evaluated by their total chromosomal lengths whereas only two 2 micron variants were defined. There was no apparent correlation between chromosomal and plasmid polymorphism. The extensive chromosomal polymorphism within one 2 micron DNA type indicates the rapid and relatively recent evolution of the nuclear genome. The hybrid origin (S. cerevisiae-S. monacensis) of lager yeast was critically evaluated by TAFE analysis of S. cerevisiae and S. carlsbergensis chromosomes. The absence of corresponding S. cerevisiae chromosomes III and XIII in S. carlsbergensis argued against the hybrid origin of lager strains. We discuss limitations of the hybrid origin hypothesis of industrial yeasts and propose that the molecular coevolution observed in 2 micron DNA serves as a useful additional mechanism for rationalization of some of the structural polymorphism of the nuclear genome.

  11. Function of trehalose and glycogen in cell cycle progression and cell viability in Saccharomyces cerevisiae

    NARCIS (Netherlands)

    Silljé, H H; Paalman, J W; ter Schure, E G; Olsthoorn, S Q; Verkleij, A J; Boonstra, Johannes; Verrips, C T

    1999-01-01

    Trehalose and glycogen accumulate in Saccharomyces cerevisiae when growth conditions deteriorate. It has been suggested that aside from functioning as storage factors and stress protectants, these carbohydrates may be required for cell cycle progression at low growth rates under carbon limitation. B

  12. The role of the nutrients in G1 phase progression of Saccharomyces cerevisiae

    NARCIS (Netherlands)

    Paalman, Johannes Wilhelmus Gerardus

    2001-01-01

    Organisms that have optimally integrated fast reproduction with high survival have a strategic advantage over less adapted species during evolution. This thesis focusses on the main decision point in the life cycle of the yeast Saccharomyces cerevisiae, at which the cell decides to rapidly grow and

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

    Science.gov (United States)

    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.

  14. Ctk1 function is necessary for full translation initiation activity in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Coordes, Britta; Brünger, Katharina M; Burger, Kaspar;

    2015-01-01

    Translation is a fundamental and highly regulated cellular process. Previously, we reported that the kinase and transcription elongation factor Ctk1 increases fidelity during translation elongation in Saccharomyces cerevisiae. Here, we show that loss of Ctk1 function also affects the initiation s...

  15. A mathematical model of the mating signal transduction pathway in the yeast Saccharomyces cerevisiae. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Thomas Ivan Milac

    1998-09-14

    Outline of two major goals in my proposal for this fellowship. First goal having no previous training in biology, was to become knowledgeable of the paradigms, experimental techniques, and current research interests of molecular biology. Second goal was to construct a mathematical model of the mating signal transduction pathway in the yeast Saccharomyces cerevisiae.

  16. Glucose and maltose metabolism in MIG1-disrupted and MAL-constitutive strains of Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Klein, Christopher; Olsson, Lisbeth; Rønnow, B;

    1997-01-01

    The alleviation of glucose control of maltose metabolism brought about by MIG1 disruption was compared to that by MAL overexpression in a haploid Saccharomyces cerevisiae strain. The sugar consumption profiles during cultivation of the wild type, single transformants and a double transformant in ...

  17. DNA Topoisomerases Maintain Promoters in a State Competent for Transcriptional Activation in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Pedersen, Jakob Madsen; Fredsøe, Jacob Christian; Rødgaard, Morten Terpager;

    2012-01-01

    To investigate the role of DNA topoisomerases in transcription, we have studied global gene expression in Saccharomyces cerevisiae cells deficient for topoisomerases I and II and performed single-gene analyses to support our findings. The genome-wide studies show a general transcriptional down-re...... transcriptional activation of genes with a repressible/inducible mode of regulation....

  18. Conditions With High Intracellular Glucose Inhibit Sensing Through Glucose Sensor Snf3 in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Karhumaa, Kaisa; Wu, B.Q.; Kielland-Brandt, Morten

    2010-01-01

    Gene expression in micro-organisms is regulated according to extracellular conditions and nutrient concentrations. In Saccharomyces cerevisiae, non-transporting sensors with high sequence similarity to transporters, that is, transporter-like sensors, have been identified for sugars as well...

  19. Production of Dengue 2 Envelope Protein in the Yeast Saccharomyces Cerevisiae. Phase 1

    Science.gov (United States)

    1990-02-15

    developing subunit dengue vaccines or recombinant live viral vaccines. Subunit vaccines may eventually include synthetic dengue peptides or recombinant... dengue proteins expressed in microorganisms, and live viral vectors such as vaccinia may express in vivo immunogenic dengue peptides . Durin...PRODUCTION OF DENGUE 2 ENVELOPE PROTEIN IN THE YEAST SACCHAROMYCES CEREVISIAE FINAL, PHASE I REPORT JOHN M. IVY KATHY HOUTCHENS FEBRUARY 15, 1990

  20. Production of bioethanol and associated by-products from potato starch residue stream by Saccharomyces cerevisiae

    Energy Technology Data Exchange (ETDEWEB)

    Hashem, Mohamed [King Khalid University, Faculty of Science, Biological Science Department, P.O. Box 10255, Abha 61321 (Saudi Arabia); Darwish, Soumia M.I. [Department of Food Science and Technology, Faculty of Agriculture, Assiut University (Egypt)

    2010-07-15

    Potato starch residue stream produced during chips manufacturing was used as an economical source for biomass and bioethanol production by Saccharomyces cerevisiae. Results demonstrated that 1% H{sub 2}SO{sub 4} at 100 C for 1 h was enough to hydrolyze all starch contained in the residue stream. Two strains of S. cerevisiae (y-1646 and commercial one) were able to utilize and ferment the acid-treated residue stream under both aerobic and semi-anaerobic conditions. The maximum yield of ethanol (5.52 g L{sup -1}) was achieved at 35 C by S. cerevisiae y-1646 after 36 h when ZnCl{sub 2} (0.4 g L{sup -1}) was added. Addition of NH{sub 4}NO{sub 3} as a source of nitrogen did not significantly affect either growth or ethanol production by S. cerevisiae y-1646. Some secondary by-products including alcohol derivatives and medical active compound were found to be associated with the ethanol production process. (author)

  1. Increased copper bioremediation ability of new transgenic and adapted Saccharomyces cerevisiae strains.

    Science.gov (United States)

    Geva, Polina; Kahta, Rotem; Nakonechny, Faina; Aronov, Stella; Nisnevitch, Marina

    2016-10-01

    Environmental pollution with heavy metals is a very serious ecological problem, which can be solved by bioremediation of metal ions by microorganisms. Yeast cells, especially Saccharomyces cerevisiae, are known to exhibit a good natural ability to remove heavy metal ions from an aqueous phase. In the present work, an attempt was made to increase the copper-binding properties of S. cerevisiae. For this purpose, new strains of S. cerevisiae were produced by construction and integration of recombinant human MT2 and GFP-hMT2 genes into yeast cells. The ySA4001 strain expressed GFP-hMT2p under the constitutive pADH1 promoter and the ySA4002 and ySA4003 strains expressed hMT2 and GFP-hMT2 under the inducible pCUP1 promoter. An additional yMNWTA01 strain was obtained by adaptation of the BY4743 wild type S. cerevisiae strain to high copper concentrations. The yMNWTA01, ySA4002, and ySA4003 strains exhibited an enhanced ability for copper ion bioremediation.

  2. Malic acid production by Saccharomyces cerevisiae: engineering of pyruvate carbosylation, oxaloacetate reduction and malate export

    NARCIS (Netherlands)

    Zelle, R.M.; Hulster, de E.; Winden, van W.A.; Waard, de P.; Dijkema, C.; Winkler, A.A.; Geertman, J.M.A.

    2008-01-01

    Malic acid is a potential biomass-derivable "building block" for chemical synthesis. Since wild-type Saccharomyces cerevisiae strains produce only low levels of malate, metabolic engineering is required to achieve efficient malate production with this yeast. A promising pathway for malate production

  3. Malic Acid Production by Saccharomyces cerevisiae: Engineering of Pyruvate Carboxylation, Oxaloacetate Reduction, and Malate Export

    NARCIS (Netherlands)

    Zelle, R.M.; De Hulster, E.; Van Winden, W.A.; De Waard, P.; Dijkema, C.; Winkler, A.A.; Geertman, J.M.; Van Dijken, J.P.; Pronk, J.T.; Van Maris, A.J.A.

    2008-01-01

    Malic acid is a potential biomass-derivable "building block" for chemical synthesis. Since wild-type Saccharomyces cerevisiae strains produce only low levels of malate, metabolic engineering is required to achieve efficient malate production with this yeast. A promising pathway for malate production

  4. Evidence of Natural Hybridization in Brazilian Wild Lineages of Saccharomyces cerevisiae.

    Science.gov (United States)

    Barbosa, Raquel; Almeida, Pedro; Safar, Silvana V B; Santos, Renata Oliveira; Morais, Paula B; Nielly-Thibault, Lou; Leducq, Jean-Baptiste; Landry, Christian R; Gonçalves, Paula; Rosa, Carlos A; Sampaio, José Paulo

    2016-01-18

    The natural biology of Saccharomyces cerevisiae, the best known unicellular model eukaryote, remains poorly documented and understood although recent progress has started to change this situation. Studies carried out recently in the Northern Hemisphere revealed the existence of wild populations associated with oak trees in North America, Asia, and in the Mediterranean region. However, in spite of these advances, the global distribution of natural populations of S. cerevisiae, especially in regions were oaks and other members of the Fagaceae are absent, is not well understood. Here we investigate the occurrence of S. cerevisiae in Brazil, a tropical region where oaks and other Fagaceae are absent. We report a candidate natural habitat of S. cerevisiae in South America and, using whole-genome data, we uncover new lineages that appear to have as closest relatives the wild populations found in North America and Japan. A population structure analysis revealed the penetration of the wine genotype into the wild Brazilian population, a first observation of the impact of domesticated microbe lineages on the genetic structure of wild populations. Unexpectedly, the Brazilian population shows conspicuous evidence of hybridization with an American population of Saccharomyces paradoxus. Introgressions from S. paradoxus were significantly enriched in genes encoding secondary active transmembrane transporters. We hypothesize that hybridization in tropical wild lineages may have facilitated the habitat transition accompanying the colonization of the tropical ecosystem.

  5. Computational Analysis of Signal Peptide-Dependent Secreted Proteins in Saccharomyces cerevisiae

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Computer based software such as the SignalP v3.0, TargetP vl.01, big-PI predictor and TMHMM v2.0 were combined to predict the signal peptides, and the signal peptide-dependent secreted proteins among the 6 700 ORFs in genome of Saccharomyces cerevisiae. The results showed that 163 proteins were the secreted ones containing signal peptides, and they were secreted via Sec pathway. Among the 163 predicted secreted proteins, the signal peptides of 47 secreted proteins included only the H-domain and C-domain, without N-domain, but the signal peptides of other 116 secreted proteins included all the three domains. There were differences in the constitution of signal peptides between the secreted proteins of S. cerevisiae and of Candida albicans, but the length and amino acids types of their signal peptides were similar in general. Few of the same signal peptides occurred in the secreted proteins of S. cerevisiae genome, and the homology could be compared among the secreted proteins with the same signal peptides. The BLAST 2 SEQUENECES and CLUSTAL W were used to align the two protein sequences and multi-protein sequences, respectively. The alignment result indicated that homology of these sequences with the same signal peptide was very highly conservative in amino acid of complete gene. The effect of the signal peptides in S. cerevisia on expression of foreign eukaryotic secreted proteins is discussed in this paper.

  6. PRIMARY STRUCTURE OF THE P450 LANOSTEROL DEMETHYLASE GENE FROM SACCHAROMYCES CEREVISIAE

    Science.gov (United States)

    We have sequenced the structural gene and flanking regions for lanosterol 14 alpha-demethylase (14DM) from Saccharomyces cerevisiae. An open reading frame of 530 codons encodes a 60.7-kDa protein. When this gene is disrupted by integrative transformation, the resulting strain req...

  7. The aspartic proteinase from Saccharomyces cerevisiae folds its own inhibitor into a helix

    DEFF Research Database (Denmark)

    Li, M; Phylip, L H; Lees, W E;

    2000-01-01

    Aspartic proteinase A from yeast is specifically and potently inhibited by a small protein called IA3 from Saccharomyces cerevisiae. Although this inhibitor consists of 68 residues, we show that the inhibitory activity resides within the N-terminal half of the molecule. Structures solved at 2...

  8. An oxalyl-CoA synthetase is important for oxalate metabolism in Saccharomyces cerevisiae

    Science.gov (United States)

    Although oxalic acid is common in nature, our understanding of the mechanism(s) regulating its turnover remains incomplete. In this study we identify Saccharomyces cerevisiae acyl-activating enzyme 3 (ScAAE3) as an enzyme capable of catalyzing the conversion of oxalate to oxalyl-CoA. Based on our fi...

  9. Dual utilization of NADPH and NADH cofactors enhances xylitol production in engineered Saccharomyces cerevisiae.

    Science.gov (United States)

    Jo, Jung-Hyun; Oh, Sun-Young; Lee, Hyeun-Soo; Park, Yong-Cheol; Seo, Jin-Ho

    2015-12-01

    Xylitol, a natural sweetener, can be produced by hydrogenation of xylose in hemicelluloses. In microbial processes, utilization of only NADPH cofactor limited commercialization of xylitol biosynthesis. To overcome this drawback, Saccharomyces cerevisiae D452-2 was engineered to express two types of xylose reductase (XR) with either NADPH-dependence or NADH-preference. Engineered S. cerevisiae DWM expressing both the XRs exhibited higher xylitol productivity than the yeast strain expressing NADPH-dependent XR only (DWW) in both batch and glucose-limited fed-batch cultures. Furthermore, the coexpression of S. cerevisiae ZWF1 and ACS1 genes in the DWM strain increased intracellular concentrations of NADPH and NADH and improved maximum xylitol productivity by 17%, relative to that for the DWM strain. Finally, the optimized fed-batch fermentation of S. cerevisiae DWM-ZWF1-ACS1 resulted in 196.2 g/L xylitol concentration, 4.27 g/L h productivity and almost the theoretical yield. Expression of the two types of XR utilizing both NADPH and NADH is a promising strategy to meet the industrial demands for microbial xylitol production.

  10. Identification of novel functional domains of Rad52 in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Plate, Iben

    2006-01-01

    , som er den foretrukne reparationsmekanisme i bagegæren Saccharomyces cerevisiae, som derfor ofte anvendes som modelorganisme til at studere homolog rekombination. Reparationsvejen homolog rekombination, samt mange af de proteiner der virker i denne, er evolutionært bevaret fra gær til menneske. S....... cerevisiae er desuden nem at manipulere genetisk og der eksisterer sofistikerede in vivo assays som muliggør visualisering af reparationsprocessen ved hjælp af fluorescensmikroskopi. Rad52 er et vigtigt protein til reparation af DNA DSB i S. cerevisiae og rad52Δ celler har en alvorlig fænotype med langsom...... betingelser. Ovennævnte studie præsenterer for første gang tilstedeværelsen af tre nye funktionelle domæner i S. cerevisiae Rad52. Det understreger vigtigheden af Rad52, dette multifunktionelle protein i homolog rekombination og giver ny forståelse for en reparationsmekanisme, som er så vigtig...

  11. Dynamic Metabolic Footprinting Reveals the Key Components of Metabolic Network in Yeast Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Chumnanpuen, Pramote; Hansen, Michael Adsetts Edberg; Smedsgaard, Jørn;

    2014-01-01

    relies on analysis at a single time point. Using direct infusion-mass spectrometry (DI-MS), we could observe the dynamic metabolic footprinting in yeast S. cerevisiae BY4709 (wild type) cultured on 3 different C-sources (glucose, glycerol, and ethanol) and sampled along 10 time points with 5 biological...

  12. Modulation of the acute phase response in feedlot steers supplemented with Saccharomyces cerevisiae

    Science.gov (United States)

    This study was designed to determine the effect of supplementing feedlot steers with Saccharomyces cerevisiae CNCM I-1079 (SC) on the acute phase response to a lipopolysaccharide (LPS) challenge. Steers (n = 18; 266 ± 4 kilograms body weight) were separated into three treatment groups (n = 6/treatm...

  13. Investigating genotype-phenotype relationships in Saccharomyces cerevisiae metabolic network through stoichiometric modeling

    DEFF Research Database (Denmark)

    Brochado, Ana Rita

    . This chapter aims at providing the reader with relevant state-of-the-art information concerning Systems Biology, Genome-Scale Metabolic Modeling and Metabolic Engineering. Particular attention is given to the yeast Saccharomyces cerevisiae, the eukaryotic model organism used thought the thesis....

  14. Dissection of transcriptional regulation networks and prediction of gene functions in Saccharomyces cerevisiae

    NARCIS (Netherlands)

    Boorsma, A.

    2008-01-01

    Molecular biology aims to unravel the functions of cells by studying cellular processes at the molecular level. Amodel organism that is well established in molecular biology is bakers yeast (Saccharomyces cerevisiae). Bakers yeast cells are remarkably similar to human cells, but much easier to grow

  15. The significance of peroxisome function in chronological aging of Saccharomyces cerevisiae

    NARCIS (Netherlands)

    Lefevre, Sophie D.; van Roermund, Carlo W.; Wanders, Ronald J. A.; Veenhuis, Marten; van der Klei, Ida J.

    2013-01-01

    Summary We studied the chronological lifespan of glucose-grown Saccharomyces cerevisiae in relation to the function of intact peroxisomes. We analyzed four different peroxisome-deficient (pex) phenotypes. These included Delta pex3 cells that lack peroxisomal membranes and in which all peroxisomal pr

  16. Acquisition and processing of a conditional dicentric chromosome in Saccharomyces cerevisiae.

    OpenAIRE

    Hill, A.; Bloom, K.

    1989-01-01

    The introduction of a conditional centromere into chromosome III of Saccharomyces cerevisiae provided an opportunity to evaluate phenotypic and karyotypic consequences in cells harboring dicentric chromosomes upon entry into mitosis. A mitotic pause ensued, and monocentric derivatives of chromosome III were generated at a high frequency.

  17. Genome-wide transcription survey on flavour production in Saccharomyces cerevisiae

    NARCIS (Netherlands)

    Schoondermark-Stolk, S.A.; Jansen, M.D.; Verkleij, A.J.; Verrips, C.T.; Euverink, G.J.W.; Dijkhuizen, L.; Boonstra, J.

    2006-01-01

    The yeast Saccharomyces cerevisiae is widely used as aroma producer in the preparation of fermented foods and beverages. During food fermentations, secondary metabolites like 3-methyl-1-butanol, 4-methyl-2-oxopentanoate, 3-methyl-2-oxobutanoate and 3-methylbutyrate emerge. These four compounds have

  18. One-hybrid screens at the Saccharomyces cerevisiae HMR locus identify novel transcriptional silencing factors.

    Science.gov (United States)

    Andrulis, Erik D; Zappulla, David C; Alexieva-Botcheva, Krassimira; Evangelista, Carlos; Sternglanz, Rolf

    2004-01-01

    In Saccharomyces cerevisiae, genes located at the telomeres and the HM loci are subject to transcriptional silencing. Here, we report results of screening a Gal4 DNA-binding domain hybrid library for proteins that cause silencing when targeted to a silencer-defective HMR locus. PMID:15020450

  19. Engineering and Evolution of Saccharomyces cerevisiae to Produce Biofuels and Chemicals.

    Science.gov (United States)

    Turner, Timothy L; Kim, Heejin; Kong, In Iok; Liu, Jing-Jing; Zhang, Guo-Chang; Jin, Yong-Su

    2016-12-03

    To mitigate global climate change caused partly by the use of fossil fuels, the production of fuels and chemicals from renewable biomass has been attempted. The conversion of various sugars from renewable biomass into biofuels by engineered baker's yeast (Saccharomyces cerevisiae) is one major direction which has grown dramatically in recent years. As well as shifting away from fossil fuels, the production of commodity chemicals by engineered S. cerevisiae has also increased significantly. The traditional approaches of biochemical and metabolic engineering to develop economic bioconversion processes in laboratory and industrial settings have been accelerated by rapid advancements in the areas of yeast genomics, synthetic biology, and systems biology. Together, these innovations have resulted in rapid and efficient manipulation of S. cerevisiae to expand fermentable substrates and diversify value-added products. Here, we discuss recent and major advances in rational (relying on prior experimentally-derived knowledge) and combinatorial (relying on high-throughput screening and genomics) approaches to engineer S. cerevisiae for producing ethanol, butanol, 2,3-butanediol, fatty acid ethyl esters, isoprenoids, organic acids, rare sugars, antioxidants, and sugar alcohols from glucose, xylose, cellobiose, galactose, acetate, alginate, mannitol, arabinose, and lactose.

  20. Substrate Specificity of Thiamine Pyrophosphate-Dependent 2-Oxo-Acid Decarboxylases in Saccharomyces cerevisiae

    NARCIS (Netherlands)

    Romagnoli, G.; Luttik, M.A.H.; Kötter, P.; Pronk, J.T.; Daran, J.M.

    2012-01-01

    Fusel alcohols are precursors and contributors to flavor and aroma compounds in fermented beverages, and some are under investigation as biofuels. The decarboxylation of 2-oxo acids is a key step in the Ehrlich pathway for fusel alcohol production. In Saccharomyces cerevisiae, five genes share seque

  1. Metabolism of phosphatidylcholine and its implications for lipid acyl chain composition in Saccharomyces cerevisiae

    NARCIS (Netherlands)

    de Kroon, A.I.P.M.

    2007-01-01

    Phosphatidylcholine (PC) is a very abundant membrane lipid in most eukaryotes including the model organism Saccharomyces cerevisiae. Consequently, the molecular species profile of PC, i.e. the ensemble of PC molecules with acyl chains differing in number of carbon atoms and double bonds, is importan

  2. Plasma membrane electron transport in Saccharomyces cerevisiae depends on the presence of mitochondrial respiratory subunits.

    Science.gov (United States)

    Herst, Patries M; Perrone, Gabriel G; Dawes, Ian W; Bircham, Peter W; Berridge, Michael V

    2008-09-01

    Most investigations into plasma membrane electron transport (PMET) in Saccharomyces cerevisiae have focused on the inducible ferric reductase responsible for iron uptake under iron/copper-limiting conditions. In this paper, we describe a PMET system, distinct from ferric reductase, which reduces the cell-impermeable water-soluble tetrazolium dye, 2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulphophenyl)-2H-tetrazolium monosodium salt (WST-1), under normal iron/copper conditions. WST-1/1-methoxy-phenazine methosulphate reduction was unaffected by anoxia and relatively insensitive to diphenyleneiodonium. Dye reduction was increased when intracellular NADH levels were high, which, in S. cerevisiae, required deletion of numerous genes associated with NADH recycling. Genome-wide screening of all viable nuclear gene-deletion mutants of S. cerevisiae revealed that, although mitochondrial electron transport per se was not required, the presence of several nuclear and mitochondrially encoded subunits of respiratory complexes III and IV was mandatory for PMET. This suggests some form of interaction between components of mitochondrial and plasma membrane electron transport. In support of this, mitochondrial tubular networks in S. cerevisiae were shown to be located in close proximity to the plasma membrane using confocal microscopy.

  3. Performance evaluation of Pichia kluyveri, Kluyveromyces marxianus and Saccharomyces cerevisiae in industrial tequila fermentation.

    Science.gov (United States)

    Amaya-Delgado, L; Herrera-López, E J; Arrizon, Javier; Arellano-Plaza, M; Gschaedler, A

    2013-05-01

    Traditionally, industrial tequila production has used spontaneous fermentation or Saccharomyces cerevisiae yeast strains. Despite the potential of non-Saccharomyces strains for alcoholic fermentation, few studies have been performed at industrial level with these yeasts. Therefore, in this work, Agave tequilana juice was fermented at an industrial level using two non-Saccharomyces yeasts (Pichia kluyveri and Kluyveromyces marxianus) with fermentation efficiency higher than 85 %. Pichia kluyveri (GRO3) was more efficient for alcohol and ethyl lactate production than S. cerevisiae (AR5), while Kluyveromyces marxianus (GRO6) produced more isobutanol and ethyl-acetate than S. cerevisiae (AR5). The level of volatile compounds at the end of fermentation was compared with the tequila standard regulation. All volatile compounds were within the allowed range except for methanol, which was higher for S. cerevisiae (AR5) and K. marxianus (GRO6). The variations in methanol may have been caused by the Agave tequilana used for the tests, since this compound is not synthesized by these yeasts.

  4. Improving the Performance of the Granulosis Virus of Codling Moth (Lepidoptera: Tortricidae) by Adding the Yeast Saccharomyces cerevisiae with Sugar.

    Science.gov (United States)

    Knight, Alan L; Basoalto, Esteban; Witzgall, Peter

    2015-04-01

    Studies were conducted with the codling moth granulosis virus (CpGV) to evaluate whether adding the yeast Saccharomyces cerevisiae Meyen ex E. C. Hansen with brown cane sugar could improve larval control of Cydia pomonella (L.). Larval mortalities in dipped-apple bioassays with S. cerevisiae or sugar alone were not significantly different from the water control. The addition of S. cerevisiae but not sugar with CpGV significantly increased larval mortality compared with CpGV alone. The combination of S. cerevisiae and sugar with CpGV significantly increased larval mortality compared with CpGV plus either additive alone. The addition of S. cerevisiae improved the efficacy of CpGV similarly to the use of the yeast Metschnikowia pulcherrima (isolated from field-collected larvae). The proportion of uninjured fruit in field trials was significantly increased with the addition of S. cerevisiae and sugar to CpGV compared with CpGV alone only in year 1, and from the controls in both years. In comparison, larval mortality was significantly increased in both years with the addition of S. cerevisiae and sugar with CpGV compared with CpGV alone or from the controls. The numbers of overwintering larvae on trees was significantly reduced from the control following a seasonal program of CpGV plus S. cerevisiae and sugar. The addition of a microencapsulated formulation of pear ester did not improve the performance of CpGV or CpGV plus S. cerevisiae and sugar. These data suggest that yeasts can enhance the effectiveness of the biological control agent CpGV, in managing and maintaining codling moth at low densities.

  5. Comparison between two selected Saccharomyces cerevisiae strains as fermentation starters in the production of traditional cachaça

    OpenAIRE

    Fátima de Cássia Oliveira Gomes; Roberta Amália de Carvalho Araújo; Patrícia Silva Cisalpino; Elizabeth Spangler Andrade Moreira; Carlos Leomar Zani; Carlos Augusto Rosa

    2009-01-01

    Two Saccharomyces cerevisiae strains were tested as the starter yeasts in a traditional cachaça distillery. The strains used were S. cerevisiae UFMG-A829, isolated from a cachaça fermentation process, and S. cerevisiae K1-V1116, obtained from the wine industry. The permanence of each strain in the fermentation must was determined by RAPD (Random Amplified Polymorphic DNA)-PCR, with primer M13. Both yeast strains were prevalent in the vats for approximately 30 days. Indigenous non-Saccharomyce...

  6. Increasing cocoa butter-like lipid production of Saccharomyces cerevisiae by expression of selected cocoa genes.

    Science.gov (United States)

    Wei, Yongjun; Gossing, Michael; Bergenholm, David; Siewers, Verena; Nielsen, Jens

    2017-12-01

    Cocoa butter (CB) extracted from cocoa beans mainly consists of three different kinds of triacylglycerols (TAGs), 1,3-dipalmitoyl-2-oleoyl-glycerol (POP, C16:0-C18:1-C16:0), 1-palmitoyl-3-stearoyl-2-oleoyl-glycerol (POS, C16:0-C18:1-C18:0) and 1,3-distearoyl-2-oleoyl-glycerol (SOS, C18:0-C18:1-C18:0), but CB supply is limited. Therefore, CB-like lipids (CBL, which are composed of POP, POS and SOS) are in great demand. Saccharomyces cerevisiae produces TAGs as storage lipids, which are also mainly composed of C16 and C18 fatty acids. However, POP, POS and SOS are not among the major TAG forms in yeast. TAG synthesis is mainly catalyzed by three enzymes: glycerol-3-phosphate acyltransferase (GPAT), lysophospholipid acyltransferase (LPAT) and diacylglycerol acyltransferase (DGAT). In order to produce CBL in S. cerevisiae, we selected six cocoa genes encoding GPAT, LPAT and DGAT potentially responsible for CB biosynthesis from the cocoa genome using a phylogenetic analysis approach. By expressing the selected cocoa genes in S. cerevisiae, we successfully increased total fatty acid production, TAG production and CBL production in some S. cerevisiae strains. The relative CBL content in three yeast strains harboring cocoa genes increased 190, 230 and 196% over the control strain, respectively; especially, the potential SOS content of the three yeast strains increased 254, 476 and 354% over the control strain. Moreover, one of the three yeast strains had a 2.25-fold increased TAG content and 6.7-fold higher level of CBL compared with the control strain. In summary, CBL production by S. cerevisiae were increased through expressing selected cocoa genes potentially involved in CB biosynthesis.

  7. Functional expression of a heterologous nickel-dependent, ATP-independent urease in Saccharomyces cerevisiae.

    Science.gov (United States)

    Milne, N; Luttik, M A H; Cueto Rojas, H F; Wahl, A; van Maris, A J A; Pronk, J T; Daran, J M

    2015-07-01

    In microbial processes for production of proteins, biomass and nitrogen-containing commodity chemicals, ATP requirements for nitrogen assimilation affect product yields on the energy producing substrate. In Saccharomyces cerevisiae, a current host for heterologous protein production and potential platform for production of nitrogen-containing chemicals, uptake and assimilation of ammonium requires 1 ATP per incorporated NH3. Urea assimilation by this yeast is more energy efficient but still requires 0.5 ATP per NH3 produced. To decrease ATP costs for nitrogen assimilation, the S. cerevisiae gene encoding ATP-dependent urease (DUR1,2) was replaced by a Schizosaccharomyces pombe gene encoding ATP-independent urease (ure2), along with its accessory genes ureD, ureF and ureG. Since S. pombe ure2 is a Ni(2+)-dependent enzyme and Saccharomyces cerevisiae does not express native Ni(2+)-dependent enzymes, the S. pombe high-affinity nickel-transporter gene (nic1) was also expressed. Expression of the S. pombe genes into dur1,2Δ S. cerevisiae yielded an in vitro ATP-independent urease activity of 0.44±0.01 µmol min(-1) mg protein(-1) and restored growth on urea as sole nitrogen source. Functional expression of the Nic1 transporter was essential for growth on urea at low Ni(2+) concentrations. The maximum specific growth rates of the engineered strain on urea and ammonium were lower than those of a DUR1,2 reference strain. In glucose-limited chemostat cultures with urea as nitrogen source, the engineered strain exhibited an increased release of ammonia and reduced nitrogen content of the biomass. Our results indicate a new strategy for improving yeast-based production of nitrogen-containing chemicals and demonstrate that Ni(2+)-dependent enzymes can be functionally expressed in S. cerevisiae.

  8. Expression of an endoglucanase from Tribolium castaneum (TcEG1) in Saccharomyces cerevisiae.

    Science.gov (United States)

    Shirley, Derek; Oppert, Cris; Reynolds, Todd B; Miracle, Bethany; Oppert, Brenda; Klingeman, William E; Jurat-Fuentes, Juan Luis

    2014-10-01

    Insects are a largely unexploited resource in prospecting for novel cellulolytic enzymes to improve the production of ethanol fuel from lignocellulosic biomass. The cost of lignocellulosic ethanol production is expected to decrease by the combination of cellulose degradation (saccharification) and fermentation of the resulting glucose to ethanol in a single process, catalyzed by the yeast Saccharomyces cerevisiae transformed to express efficient cellulases. While S. cerevisiae is an established heterologous expression system, there are no available data on the functional expression of insect cellulolytic enzymes for this species. To address this knowledge gap, S. cerevisiae was transformed to express the full-length cDNA encoding an endoglucanase from the red flour beetle, Tribolium castaneum (TcEG1), and evaluated the activity of the transgenic product (rTcEG1). Expression of the TcEG1 cDNA in S. cerevisiae was under control of the strong glyceraldehyde-3 phosphate dehydrogenase promoter. Cultured transformed yeast secreted rTcEG1 protein as a functional β-1,4-endoglucanase, which allowed transformants to survive on selective media containing cellulose as the only available carbon source. Evaluation of substrate specificity for secreted rTcEG1 demonstrated endoglucanase activity, although some activity was also detected against complex cellulose substrates. Potentially relevant to uses in biofuel production rTcEG1 activity increased with pH conditions, with the highest activity detected at pH 12. Our results demonstrate the potential for functional production of an insect cellulase in S. cerevisiae and confirm the stability of rTcEG1 activity in strong alkaline environments.

  9. Engineering cellular redox balance in Saccharomyces cerevisiae for improved production of L-lactic acid.

    Science.gov (United States)

    Lee, Ju Young; Kang, Chang Duk; Lee, Seung Hyun; Park, Young Kyoung; Cho, Kwang Myung

    2015-04-01

    Owing to the growing market for the biodegradable and renewable polymer, polylactic acid, world demand for lactic acid is rapidly increasing. However, the very high concentrations desired for industrial production of the free lactic acid create toxicity and low pH concerns for manufacturers. Saccharomyces cerevisiae is the most well characterized eukaryote, a preferred microbial cell factory for the largest industrial biotechnology product (bioethanol), and a robust, commercially compatible workhorse to be exploited for the production of diverse chemicals. S. cerevisiae has also been explored as a host for lactic acid production because of its high acid tolerance. Here, we constructed an L-lactic acid-overproducing S. cerevisiae by redirecting cellular metabolic fluxes to the production of L-lactic acid. To this end, we deleted the S. cerevisiae genes encoding pyruvate decarboxylase 1 (PDC1), L-lactate cytochrome-c oxidoreductase (CYB2), and glycerol-3-phosphate dehydrogenase (GPD1), replacing them with a heterologous L-lactate dehydrogenase (LDH) gene. Two new target genes encoding isoenzymes of the external NADH dehydrogenase (NDE1 and NDE2), were also deleted from the genome to re-engineer the intracellular redox balance. The resulting strain was found to produce L-lactic acid more efficiently (32.6% increase in final L-lactic acid titer). When tested in a bioreactor in fed-batch mode, this engineered strain produced 117 g/L of L-lactic acid under low pH conditions. This result demonstrates that the redox balance engineering should be coupled with the metabolic engineering in the construction of L-lactic acid-overproducing S. cerevisiae.

  10. Changes of Saccharomyces cerevisiae cell membrane components and promotion to ethanol tolerance during the bioethanol fermentation.

    Science.gov (United States)

    Dong, Shi-Jun; Yi, Chen-Feng; Li, Hao

    2015-12-01

    During bioethanol fermentation process, Saccharomyces cerevisiae cell membrane might provide main protection to tolerate accumulated ethanol, and S. cerevisiae cells might also remodel their membrane compositions or structure to try to adapt to or tolerate the ethanol stress. However, the exact changes and roles of S. cerevisiae cell membrane components during bioethanol fermentation still remains poorly understood. This study was performed to clarify changes and roles of S. cerevisiae cell membrane components during bioethanol fermentation. Both cell diameter and membrane integrity decreased as fermentation time lasting. Moreover, compared with cells at lag phase, cells at exponential and stationary phases had higher contents of ergosterol and oleic acid (C18:1) but lower levels of hexadecanoic (C16:0) and palmitelaidic (C16:1) acids. Contents of most detected phospholipids presented an increase tendency during fermentation process. Increased contents of oleic acid and phospholipids containing unsaturated fatty acids might indicate enhanced cell membrane fluidity. Compared with cells at lag phase, cells at exponential and stationary phases had higher expressions of ACC1 and HFA1. However, OLE1 expression underwent an evident increase at exponential phase but a decrease at following stationary phase. These results indicated that during bioethanol fermentation process, yeast cells remodeled membrane and more changeable cell membrane contributed to acquiring higher ethanol tolerance of S. cerevisiae cells. These results highlighted our knowledge about relationship between the variation of cell membrane structure and compositions and ethanol tolerance, and would contribute to a better understanding of bioethanol fermentation process and construction of industrial ethanologenic strains with higher ethanol tolerance.

  11. Expression of Selected <em>Ginkgo em>>biloba em>Heat Shock Protein Genes After Cold Treatment Could Be Induced by Other Abiotic Stress

    Directory of Open Access Journals (Sweden)

    Feng Xu

    2012-05-01

    Full Text Available Heat shock proteins (HSPs play various stress-protective roles in plants. In this study, three <em>HSP> genes were isolated from a suppression subtractive hybridization (SSH cDNA library of <em>Ginkgo bilobaem> leaves treated with cold stress. Based on the molecular weight, the three genes were designated <em>GbHSP16.8em>, <em>GbHSP17em> and <em>GbHSP70em>. The full length of the three genes were predicted to encode three polypeptide chains containing 149 amino acids (Aa, 152 Aa, and 657 Aa, and their corresponding molecular weights were predicted as follows: 16.67 kDa, 17.39 kDa, and 71.81 kDa respectively. The three genes exhibited distinctive expression patterns in different organs or development stages. <em>GbHSP16.8em> and <em>GbHSP70em> showed high expression levels in leaves and a low level in gynoecia, <em>GbHSP17em> showed a higher transcription in stamens and lower level in fruit. This result indicates that <em>GbHSP16.8em> and <em>GbHSP70 em>may play important roles in <em>Ginkgo> leaf development and photosynthesis, and <em>GbHSP17em> may play a positive role in pollen maturation. All three <em>GbHSPs> were up-regulated under cold stress, whereas extreme heat stress only caused up-regulation of <em>GbHSP70em>, UV-B treatment resulted in up-regulation of <em>GbHSP16.8em> and <em>GbHSP17em>, wounding treatment resulted in up-regulation of <em>GbHSP16.8em> and <em>GbHSP70em>, and abscisic acid (ABA treatment caused up-regulation of <em>GbHSP70em> primarily.

  12. A hipnose em triatletas

    OpenAIRE

    Szenészi, Daniela Scharamm

    2005-01-01

    Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Filosofia e Ciências Humanas. Programa de Pós-Graduação em Psicologia. Esta pesquisa objetivou investigar em atletas de triatlon a percepção das características da visualização da prova de Ironman e os seus componentes psicofisiológicos durante o transe hipnótico. Foram estudados 7 atletas do sexo masculino em 6 sessões de hipnose. Após cada sessão foi feita uma entrevista semi-estruturada e aplicado um questionário...

  13. Meteorologia em linha

    OpenAIRE

    2015-01-01

    DISPOSITIVO TÉCNICO-PEDAGÓGICO: CURSO DE METEOROLOGIA EM LINHA. Designamos por curso o sistema que resulta da relação entre um conjunto de componentes, dando unidade e identidade ao mesmo, incorporados na plataforma Versal: conjunto de 30 lições em vídeo, recursos complementares, valorização e contextualização do curso, orientação e acompanhamento desenhados e previstos, interação com os utilizadores do curso a partir do momento da sua edição aberta em linha. (https://versal.com/c/1fzwaz/m...

  14. Osteoartrites em equinos

    OpenAIRE

    Rocha, Francisco José Martins

    2008-01-01

    Dissertação de Mestrado Integrado em Medicina Veterinária A Osteoartrite (OA) é a principal causa de claudicação no cavalo de desporto e lazer, sendo uma afecção que tem grandes repercussões económicas. Este trabalho descreve algumas das características importantes da estrutura articular, bem como da sua fisiologia. Define a OA e todas as estruturas envolvidas no seu processo. Os mecanismos fisiopatológicos põem em evidência os factores de risco em causa e que determinam tod...

  15. Pesquisando em fontes visuais

    OpenAIRE

    Proença, Caio Carvalho; FFCH

    2012-01-01

    O presente ensaio pretende demonstrar reflexões sobre os usos da fotografia como fonte. Na primeira parte do ensaio procura-se demonstrar a experiência de um primeiro contato com a fonte visual, em especial a fotografia, para posteriormente entrar em contato com as diferentes formas metodológicas presente na pesquisa desta fonte. Em um segundo momento mostra-se alguns apontamentos sobre o método de pesquisa voltado à fonte visual fotográfica que auxiliam a pesquisa, contemplando a discussão s...

  16. Melhores medicamentos em Pediatria

    OpenAIRE

    2014-01-01

    Resumo: Existem actualmente muitos medicamentos que são utilizados em crianças sem terem sido suficientemente estudados nas diferentes sub-populações pediátricas, com consequências preocupantes. O reconhecimento deste facto levou à criação de regras específicas na investigação de medicamentos pediátricos nos EUA, já em 1997. De igual forma, o Regulamento de Medicamentos para Uso Pediátrico aprovado em De zembro de 2006 pelo Parlamento Europeu, tem como objectivo a resolução deste problema no ...

  17. Characterization of <em>Erysiphe necatorem>-Responsive Genes in Chinese Wild <em>Vitis> <em>quinquangularis>

    Directory of Open Access Journals (Sweden)

    Xiping Wang

    2012-09-01

    Full Text Available Powdery mildew (PM, caused by fungus <em>Erysiphe necatorem>, is one of the most devastating diseases of grapevine. To better understand grapevine-PM interaction and provide candidate resources for grapevine breeding, a suppression subtractive hybridization (SSH cDNA library was constructed from <em>E. necatorem>-infected leaves of a resistant Chinese wild <em>Vitis quinquangularisem> clone “Shang-24”. A total of 492 high quality expressed sequence tags (ESTs were obtained and assembled into 266 unigenes. Gene ontology (GO analysis indicated that 188 unigenes could be assigned with at least one GO term in the biological process category, and 176 in the molecular function category. Sequence analysis showed that a large number of these genes were homologous to those involved in defense responses. Genes involved in metabolism, photosynthesis, transport and signal transduction were also enriched in the library. Expression analysis of 13 selected genes by qRT-PCR revealed that most were induced more quickly and intensely in the resistant material “Shang-24” than in the sensitive <em>V. pseudoreticulata em>clone “Hunan-1” by<em> E. necatorem> infection. The ESTs reported here provide new clues to understand the disease-resistance mechanism in Chinese wild grapevine species and may enable us to investigate <em>E. necatorem>-responsive genes involved in PM resistance in grapevine germplasm.

  18. International EMS Systems

    DEFF Research Database (Denmark)

    Langhelle, Audun; Lossius, Hans Morten; Silfvast, Tom;

    2004-01-01

    Emergency medicine service (EMS) systems in the five Nordic countries have more similarities than differences. One similarity is the involvement of anaesthesiologists as pre-hospital physicians and their strong participation for all critically ill and injured patients in-hospital. Discrepancies do...... exist, however, especially within the ground and air ambulance service, and the EMS systems face several challenges. Main problems and challenges emphasized by the authors are: (1) Denmark: the dispatch centres are presently not under medical control and are without a national criteria based system....... Access to on-line medical advice of a physician is not available; (2) Finland: the autonomy of the individual municipalities and their responsibility to cover for primary and specialised health care, as well as the EMS, and the lack of supporting or demanding legislation regarding the EMS; (3) Iceland...

  19. Preconceito em disfarce

    Directory of Open Access Journals (Sweden)

    João de Almeida

    2001-02-01

    Full Text Available

    0 presente estudo pretende analisar os significados básicos do texto "Preto e Branco", de F. Sabino, valendo-se de alguns modelos teóricos lingüísticos, principalmente de Greimas e de Pottier, em seqüência que vai da estrutura da narrativa e do percurso gerativo de sentido até as relações sêmicas, em especial.

  20. Global Transcriptional and Physiological Responses of Saccharomyces cerevisiae to Ammonium, L-Alanine, or L-Glutamine Limitation

    DEFF Research Database (Denmark)

    Usaite, Renata; Patil, Kiran Raosaheb; Grotkjær, Thomas;

    2006-01-01

    The yeast Saccharomyces cerevisiae encounters a range of nitrogen sources at various concentrations in its environment. The impact of these two parameters on transcription and metabolism was studied by growing S. cerevisiae in chemostat cultures with L-glutamine, L-alanine, or L-ammonium in limit......The yeast Saccharomyces cerevisiae encounters a range of nitrogen sources at various concentrations in its environment. The impact of these two parameters on transcription and metabolism was studied by growing S. cerevisiae in chemostat cultures with L-glutamine, L-alanine, or L...... activity in L-alanine-limited cells. The changes in these cells were found to be focused around pyruvate, acetyl coenzyme A, glyoxylate, and alpha-ketoglutarate via increased levels of ALT1, DAL7, PYC1, GDH2, and ADH5 and decreased levels of GDH3, CIT2, and ACS1 transcripts. The transcript profiles were...