DEFAR - Departamento de Farmácia
URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/530
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Item High‑affinity transport, cyanide‑resistant respiration, and ethanol production under aerobiosis underlying efficient high glycerol consumption by Wickerhamomyces anomalus.(2019) Cunha, Aureliano Claret da; Gomes, Lorena Soares; Santos, Fernanda Godoy; Oliveira, Fábio Faria; Teixeira, Janaina Aparecida; Sampaio, Geraldo Magela Santos; Trópia, Maria José Magalhães; Castro, Ieso de Miranda; Lucas, Cândida Manuel Ribeiro Simões; Brandão, Rogélio LopesWickerhamomyces anomalus strain LBCM1105 was originally isolated from the wort of cachaça (the Brazilian fermented sugarcane juice-derived Brazilian spirit) and has been shown to grow exceptionally well at high amounts of glycerol. This paramount residue from the biodiesel industry is a promising cheap carbon source for yeast biotechnology. The assessment of the physiological traits underlying the W. anomalus glycerol consumption ability in opposition to Saccharomyces cerevisiae is presented. A new WaStl1 concentrative glycerol-H+ symporter with twice the affinity of S. cerevisiae was identified. As in this yeast, WaSTL1 is repressed by glucose and derepressed/induced by glycerol but much more highly expressed. Moreover, LBCM1105 aerobically growing on glycerol was found to produce ethanol, providing a redox escape to compensate the redox imbalance at the level of cyanide-resistant respiration (CRR) and glycerol 3P shuttle. This work is critical for understanding the utilization of glycerol by non-Saccharomyces yeasts being indispensable to consider their industrial application feeding on biodiesel residue.Item Deficiency of Pkc1 activity affects glycerol metabolism in Saccharomices cerevisiae.(2005) Gomes, Katia das Neves; Freitas, Suzy Magaly Alves Cabral de; Pais, Thiago Martins; Fietto, Juliana Lopes Rangel; Totola, Antonio Helvecio; Arantes, Rosa Maria Esteves; Martins, António; Lucas, Cândida Manuel Ribeiro Simões; Schuller, Dorit; Casal, Margarida; Castro, Ieso de Miranda; Fietto, Luciano Gomes; Rogelio, Lopes BrandãoProtein kinase C is apparently involved in the control of many cellular systems: the cell wall integrity pathway, the synthesis of ribosomes, the appropriated reallocation of transcription factors under specific stress conditions and also the regulation of N-glycosylation activity. All these observations suggest the existence of additional targets not yet identified. In the context of the control of carbon metabolism, previous data had demonstrated that Pkc1p might play a central role in the control of cellular growth and metabolism in yeast. In particular, it has been suggested that it might be involved in the derepression of genes under glucose-repression by driving an appropriated subcellular localization of transcriptional factors, such as Mig1p. In this work, we show that a pkc1D mutant is unable to grow on glycerol because it cannot perform the derepression of the GUT1 gene that encodes glycerol kinase. Additionally, active transport is also partially affected. Using this phenotype, we were able to isolate a new pkc1D revertant. We also isolated two transformants identified as the nuclear exportin Msn5 and the histone deacetylase Hos2 extragenic suppressors of this mutation. Based on these results, we postulate that Pkc1p may be involved in the control of the cellular localization and/or regulation of the activity of nuclear proteins implicated in gene expression.Item Protective effect of ions against cell death induced by acid stress in Saccharomyces.(2009) Sant'Ana, Gilzeane dos Santos; Paes, Lisvane da Silva; Paiva, Argentino F. Vieira; Fietto, Luciano Gomes; Tótola, Antônio Helvécio; Trópia, Maria José Magalhães; Lemos, Denise da Silveira; Lucas, Cândida Manuel Ribeiro Simões; Fietto, Juliana Lopes Rangel; Brandão, Rogélio Lopes; Castro, Ieso de MirandaSaccharomyces boulardii is a probiotic used to prevent or treat antibiotic-induced gastrointestinal disorders and acute enteritis. For probiotics to be effective they must first be able to survive the harsh gastrointestinal environment. In this work, we show that S. boulardii displayed the greatest tolerance to simulated gastric environments compared with several Saccharomyces cerevisiae strains tested. Under these conditions, a pH 2.0 was the main factor responsible for decreased cell viability. Importantly, the addition of low concentrations of sodium chloride (NaCl) protected cells in acidic conditions more effectively than other salts. In the absence of S. boulardii mutants, the protective effects of Na1 in yeast viability in acidic conditions was tested using S. cerevisiae Na1-ATPases (ena1-4), Na1/H1 antiporter (nha1D) and Na1/H1 antiporter prevacuolar (nhx1D) null mutants, respectively. Moreover, we provide evidence suggesting that this protection is determined by the plasma membrane potential, once altered by low pH and low NaCl concentrations. Additionally, the absence or low expression/activity of Ena proteins seems to be closely related to the basal membrane potential of the cells.