947 resultados para Saccharomyces cerevisiae YM4271
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The objective of this study was to evaluate the effects of sugarcane juice treatment using Moringa oleifera leaf and seeds extracts on ethanolic fermentation. The experiment was arranged in a split plot statistical design, with four replications. Main treatments were three sedimentation agents (synthetic polyelectrolyte, moringa leaf and seed extracts) and control while the secondary treatments were two sugarcane varieties (RB867515 and CTC4). Extracted sugarcane juice was clarified by simple defecation with pH adjusted to 6.0. The flocculating agents were added in a decanter before the limed juice. After then, the juice was standardized to 16° Brix at pH 4.5, and musts were inoculated with yeast Saccharomyces cerevisiae strain, FT858. At the end of the fermentation process, wines were recovered by centrifugation. In all experimental stages, extracted juice, clarified juice and wine were chemically and technologically characterized. The use of moringa leaf and seed extracts as sedimentation adjuvants did not increase the sedimentation speed of impurities. However, there was a high sludge compaction, which was essential for maintenance of yeast and bud population at the beginning of fermentation, and yeast budding rate in the end. The use of different sedimentation agents as adjuvants in juice treatment did not affect wine quality and ethanol yield.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Nas etapas fermentativas destinadas a produção de etanol, observa-se o desenvolvimento de diversos contaminantes, dentre elas as leveduras selvagens, que muitas vezes comprometem a produtividade e qualidade do produto final. Desta forma, o trabalho objetivou caracterizar, classificar e determinar marcadores genéticos-moleculares para 5 estirpes de leveduras (C69, C128, C271, CAT e Saccharomyces cerevisiae). A avaliação envolveu a determinação da assimilação de fonte de carbono e técnica de RAPD (Random Amplified Polymorphic DNA). Os resultados obtidos através dos testes de assimilação de fontes de carbono são importantes para diferenciação e caracterização de leveduras. Sendo, as leveduras C69,C128 e C271 com habilidade para desdobrar xilose como fonte de carbono. A técnica de RAPD obteve dois primers sozinhos não sendo suficientes para a geração de 100 bandas polimórficas para a população, levando-se em conta os resultados do tratamento 2 de 50ng: que pelo polimorfismo gerado pode-se discriminar três grupos principais e distintos: a amostra três sozinha, porém que ocupa uma similaridade com o grupo formado pelo controle e a estirpe 4, e por último o grupo formado pelas amostras 1 e 2, separados do anterior.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Pós-graduação em Geociências e Meio Ambiente - IGCE
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Pós-graduação em Biotecnologia - IQ
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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The objective of this work was to evaluate the relationship between phenolic compounds and alcoholic fermentation efficiency. The yield of sugarcanebyproducts (glycerol, acidity, and biomass) was determined in a continuous process at SaoManoel Sugarcane Mill, (Sao Paulo, Brazil) during the 2011/2012 harvest period. The Saccharomyces cerevisiae strain used as inoculum was the CAT-1. During the harvest, the endogenous yeast outcompeted the selected strain, hence eliminating it from the process. This research consists of a case of study on the ethanol production facility. FolinCiocauteau and methylene blue method was used to assess phenolic compounds. The efficiencyof the byproducts generated during the fermentation processwas calculated. Statistics analyses were carried out using Pearson correlation and its significance, by thet-test. We concluded that the phenolic compounds within the must could not be correlated to the byproducts’fermentation efficiency calculated during a continuous fermentation process.
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Pós-graduação em Zootecnia - FCAV
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The cAMP signal transduction pathway controls a wide variety of processes in fungi. For example, considerable progress has been made in describing the involvement of cAMP pathway components in the control of morphogenesis in Saccharomyces cerevisiae, Ustilago maydis, and Magnaporthe grisea. These morphological processes include the establishment of filamentous growth in S. cerevisiae and U. maydis, and the differentiation of an appressorial infection structure in M. grisea. The discovery that appressorium formation requires cAMP signaling provides an immediate connection to fungal virulence. This connection may have broader implications among fungal pathogens because recent work indicates that cAMP signaling controls the expression of virulence traits in the human pathogen Cryptococcus neoformans. In this fungus, cAMP also influences mating, as has been found for Schizosaccharomyces pombe and as may occur in U. maydis. Finally, cAMP and mitogen- activated protein kinase pathways appear to function coordinately to control the response of certain fungi, e.g., Saccharomyces cerevisiae and Schizosaccharomyces pombe, to environmental stress. There are clues that interconnections between these pathways may be common in the control of many fungal processes.
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Candida albicans is a common opportunistic, dimorphic human fungal pathogen. One of its virulence factors is the morphological switch between yeasts and hyphal or pseudohyphal forms, which can invade tissues and cause damage. Our studies focus on factors regulating pseudohyphae and epigenetic modifications of C. albicans. Regulating factors of pseudohyphae are aromatic alcohols and high phosphate. At low concentrations, exogenous aromatic alcohols induced pseudohyphae, as did high phosphate. For addressing the pathways involved in inducing pseudohyphae by aromatic alcohols or high phosphate, we used mutants defective in cAMP dependent PKA pathway (efg1/efg1), MAP kinase pathway (cph1/cph1), or both (cph1/cph1/efg1/efg1). These mutants failed to produce either hyphae or pseudohyphae in the presence of aromatic alcohols; but high phosphate still stimulated pseudohyphae. Gcn4, a transcription activator of more than 500 amino acid related genes, is turned-on in response to amino acid starvation. The accumulation of aromatic alcohols sends nitrogen starvation signals, which inhibit eIF2B, which in turn derepresses Gcn4p. High phosphate also induces pseudohyphae by derepressing Gcn4p, although the pathways involved are still unknown. In sum, aromatic alcohols and high phosphate induce pseudohyphae by derepressing Gcn4. In this study we found a novel posttranslational histone modification in C. albicans, which is biotinylation. Western blot and Mass spectrometry techniques were used to find that Histones H2B and H4 were biotinylated at every condition tested such as yeast vs. hyphae, aerobic growth vs. anaerobic growth, rich medium vs. defined medium. In C. albicans lysines K8, K11 in histone H4 and lysines K17, K18, K31 in histone H2B are biotin attachment sites as found using mass spectrometry. Biotin was also found to enhance the germ tube formation of C. albicans. Germ tube formation assays with biotin-starved cells as inoculum showed low percent of germ tubes (1-5%). Addition of biotin to the media showed 100% germ tubes. Biotinylation of histones were not detected from biotin-starved cells. Appendix-A details work related to Farnesol quantification assays in several strains of C.albicans and Ceratocystis ulmi, and growth studies of class E VPS strains of Saccharomyces Cerevisiae. Adviser: Kenneth W. Nickerson
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Nucleoli, nuclear organelles in which ribosomal RNA is synthesized and processed, emerge from nucleolar organizers (NORs) located in distinct chromosomal regions. In polytene nuclei of dipterans, nucleoli of some species can be observed under light microscopy exhibiting distinctive morphology: Drosophila and chironomid species display well-formed nucleoli in contrast to the fragmented and dispersed nucleoli seen in sciarid flies. The available data show no apparent relationship between nucleolar morphology and location of NORs in Diptera. The regulation of rRNA transcription involves controlling both the transcription rate per gene as well as the proportion of rRNA genes adopting a proper chromatin structure for transcription, since active and inactive rRNA gene copies coexist in NORs. Transcription units organized in nucleosomes and those lacking canonical nucleosomes can be analyzed by the method termed psoralen gel retarding assay (PGRA), allowing inferences on the ratio of active to inactive rRNA gene copies. In this work, possible connections between chromosomal location of NORs and proportion of active rRNA genes were studied in Drosophila melanogaster, and in chironomid and sciarid species. The data suggested a link between location of NORs and proportion of active rRNA genes since the copy number showing nucleosomal organization predominates when NORs are located in the pericentric heterochromatin. The results presented in this work are in agreement with previous data on the chromatin structure of rRNA genes from distantly related eukaryotes, as assessed by the PGRA.
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Significant amounts of wastes are generated by the coffee industry, among of which, coffee silverskin (CS) and spent coffee grounds (SCG) are the most abundantly generated during the beans roasting and instant coffee preparation, respectively. This study evaluated the sugars metabolism and production of ethanol by three different yeast strains (Saccharomyces cerevisiae, Pichia stipitis and Kluyveromyces fragilis) when cultivated in sugar rich hydrolysates produced by acid hydrolysis of CS and SCG. S. cerevisiae provided the best ethanol production from SCG hydrolysate (11.7 g/l, 50.2% efficiency). On the other hand, insignificant (<= 1.0 g/l) ethanol production was obtained from CS hydrolysate, for all the evaluated yeast strains, probably due to the low sugars concentration present in this medium (approx. 22 g/l). It was concluded that it is possible to reuse SCG as raw material for ethanol production, which is of great interest for the production of this biofuel, as well as to add value to this agro-industrial waste. CS hydrolysate, in the way that is produced, was not a suitable fermentation medium for ethanol production; however, the hydrolysate concentration for the sugars content increase previous the use as fermentation medium could be an alternative to overcome this problem. (C) 2011 Elsevier Ltd. All rights reserved.