Sant'Ana, Gilzeane dos SantosPaes, Lisvane da SilvaPaiva, Argentino F. VieiraFietto, Luciano GomesTótola, Antônio HelvécioTrópia, Maria José MagalhãesLemos, Denise da SilveiraLucas, Cândida Manuel Ribeiro SimõesFietto, Juliana Lopes RangelBrandão, Rogélio LopesCastro, Ieso de Miranda2012-07-182012-07-182009SANT'ANA, G. dos S. et al. Protective effect of ions against cell death induced by acid stress in Saccharomyces. FEMS Yeast Research, v. 9, n.5, p.701-712, ago. 2009. Disponível em: <http://onlinelibrary.wiley.com/doi/10.1111/j.1567-1364.2009.00523.x/pdf>. Acesso em: 18 jul. 2012.15671364http://www.repositorio.ufop.br/handle/123456789/1161Saccharomyces 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.en-USAcid toleranceProbioticArtigo publicado em periodicoO Periódico FEMS Yeast Research concede permissão para depósito deste artigo no Repositório Institucional da UFOP. Número da licença: 500810556