Submitted by Liliane Ferreira (ljuvencia30@gmail.com) on 2018-02-15T12:20:35Z No. of bitstreams: 2 Dissertação - Ricardo Rezende de Morais - 2015.pdf: 1680419 bytes, checksum: cab2bfb60999f60e7f15cb69e1d9fac5 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-02-15T12:59:12Z (GMT) No. of bitstreams: 2 Dissertação - Ricardo Rezende de Morais - 2015.pdf: 1680419 bytes, checksum: cab2bfb60999f60e7f15cb69e1d9fac5 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-02-15T12:59:12Z (GMT). No. of bitstreams: 2 Dissertação - Ricardo Rezende de Morais - 2015.pdf: 1680419 bytes, checksum: cab2bfb60999f60e7f15cb69e1d9fac5 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2015-05-12 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The Solanum lycocarpum plant, commonly known as wolf gray, is a shrub or tree up to 5 m frequent throughout the Brazilian Cerrado, responsible for production wolf fruit. The objective of this work is the use of starch extracted from the fruit of S. lycocarpum as a new source for the production of ethanol by fermentation. The starch in the fruit was extracted by grinding lobeira mesocarp citric acid 0.8% (w / v) subsequent decantation. Thereafter the starch was hydrolyzed using the α-amilise and immobilized glucoamylase-glutaraldehyde polyaniline, with an average rate of glucose production of approximately 80% after 60 h. Glucose solutions at concentrations of 1%, 5% and 9% (w / v) were fermented by the yeast Saccharomyces bayanus INCQS 40235, provided by the National Institute of Quality Control in Health Oswaldo Cruz Foundation. Ethanol production was quantified by the following methods: by reducing the weight due to release of CO2 and the maximum yield obtained after 48 h of fermentation, reaching a production of 6.1704 g in 48 hours; reduction of 75.63% of the total sugar content in the fermentation broth reaching 48.4 mg mL-1 after 48 hours. The fermentation process was also evaluated by the growth of yeast cells that reached 1,407 x 108 cells in 48 hours of fermentation. Results of this work have shown that the starch extracted from the fruit of lobeira is a promising source for the production of ethanol, yielding 10.5% of ethanol after 48h fermentation using a 9% solution of hydrolyzed starch under industrial fermentation simulation. / A planta Solanum lycocarpum, conhecida popularmente como lobeira, é um arbusto ou árvore de até 5 m frequente em todo o Cerrado brasileiro, e responsável pela produção do fruto do lobo. O objetivo deste trabalho é a utilização do amido extraído do fruto da S. lycocarpum como uma nova fonte para a produção de etanol por processo fermentativo. O amido do fruto da lobeira foi extraído por trituração do mesocarpo em ácido cítrico 0.8% (p/v) e posterior decantação. Posteriormente o amido foi hidrolisado utilizando-se a α-amilase e a glicoamilase imobilizadas em polianilina-glutaraldeído, com uma produção média de glicose de aproximadamente 91%, após 60 h de reação. Soluções de glicose nas concentrações 1%, 5% e 9% (p/v) foram fermentadas pela levedura Saccharomyces bayanus INCQS 40235, fornecida pelo Instituto Nacional de Controle de Qualidade em Saúde da Fundação Oswaldo Cruz. A produção de etanol foi quantificada pela redução do peso devido ao desprendimento de CO2, sendo o máximo rendimento obtido após 48 h de fermentação, de 6,17g/ 100 mL; o que apresenta uma redução de 75,63% na concentração de açúcares totais no caldo fermentativo, chegando a 48,4 mg mL-1 após 48 horas. O processo fermentativo também foi avaliado pelo crescimento do número de células da levedura que atingiu 1,407 x 108 células em 48 horas de fermentação. Os resultados deste trabalho permitem concluir que o amido extraído do fruto da lobeira é uma fonte promissora para a produção de etanol, com rendimento de 8,64% de etanol produzido após 48h de fermentação partindo de uma solução a 9% de glicose numa simulação de escala industrial.

<p>In an attempt to gain more insight on functional evolution of cAMP-PKA pathway I have taken a comparative approach and examined functional interactions of cAMP-PKA signaling in well-studied yeast developmental programs and closely related <italic>Saccharomyces sensu stricto<italic/>. species. I have shown that variation in cAMP-PKA signaling contributes significantly to variation in developmental responses in <italic>S cerevisiae. Variation in pseudohyphal growth and sporulation, two inversely correlated developmental strategies to nutrient limitation in yeast, proportional to variation in intracellular cAMP levels. <italic>S. cerevisiae strains proficient in pseudohyphal growth have higher intracellular cAMP concentrations relative to strains that sporulate efficiently. Phenotypic, genetic and signaling data presented here suggest that the cAMP-PKA signaling underlies a phenotypic trade-off between sporulation and pseudohyphal growth in <italic>S. cerevisiae<italic/>.</p><p>Further investigation into the role of cAMP-PKA signaling in closely related <italic>S paradoxus<italic/> and <italic>S bayanus revealed an antagonistic function of cAMP-PKA signaling for developmental responses in <italic>S. bayanus. Unlike in <italic>S. cerevisiae, increased cAMP concentrations surprisingly inhibit pseudohyphal response in <italic>S. bayanus<italic/>. Another unanticipated finding in this work is that in <italic>S. bayanus<italic/>. Flo11, required for pseudohyphal differentiation in S. cerevisiae, is dispensable. Additionally, interactions of cAMP-PKA signaling and the general-stress response mechanism appear reversed in <italic>S. bayanus<italic/>. As shown by deletion mutation, gene expression and pharmacological treatment data, altered interactions and alternative targets downstream of cAMP-PKA could critically contribute to alternative regulation of nutrient-induced development in <italic>S. bayanus<italic/>.</p><p>Intracellular cAMP concentrations show decaying oscillations upon glucose replenishment in derepressed yeast cells. The quantitative characteristics of oscillations are distinct within and between Saccharomyces species. Given the tight regulation of cAMP levels and its critical role, the variation in cAMP oscillatory dynamics could be reflective of differential interactions of cAMP-PKA signaling that also underlie induction of developmental programs to changing environments. As such, intracellular cAMP levels and dynamics could potentially be used as molecular phenotypes.</p> / Dissertation

Prions are self-perpetuating and, in most cases, aggregation-prone protein isoforms that transmit neurodegenerative diseases in mammals and control heritable traits in yeast. Prion conversion requires a very high level of identity of the interacting protein sequences. Decreased transmission of the prion state between divergent proteins is termed "species barrier" and was thought to occur due to the inability of divergent prion proteins to co-aggregate. Species barrier can be overcome in cross-species infections, for example from "mad cows" to humans. We studied the counterparts of yeast prion protein Sup35, originated from three different species of the Saccharomyces sensu stricto group and exhibiting the range of prion domain divergence that overlaps with the range of divergence observed among distant mammalian species. Heterologous Sup35 proteins co-aggregated in S. cerevisiae cells. However, in vivo cross-species prion conversion was decreased and in vitro polymerization was cross-inhibited in at least some heterologous combinations, thus demonstrating the existence of prion species barrier. Our data suggests that species-specificity of prion transmission is controlled at the level of conformational transition rather than co-aggregation. We have shown the Sup35 prion domain is sufficient for the species barrier among the S. sensu stricto species, and constructed SUP35 chimeric prion domains, combining the subregions of various origins Our data demonstrated in different cross-species combinations, different modules of prion domain play a crucial role in the controlling of species-specificity of prion transmission. One essential amino acid position has been identified in S. cerevisiae and S. paradoxus system. Our data support a model suggesting that identity of the short amyloidogenic sequences is crucial for the species barrier. Sup35 originated from three different species of the S. sensu stricto group were capable of forming a prion in S. cerevisiae. However, it was not known whether they are capable of generating and maintaining the prion state in the homologous cell environment. We have constructed the S. paradoxus and S. bayanus strains with appropriate markers, and we were able to demonstrate de novo [PSI+] formation in S. paradoxus but not in S. bayanus. Our data show that [PSI+] formation is not a unique property of S. cerevisiae.