Protective effect of ions against cell death induced by acid stress in Saccharomyces.
Saccharomyces 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 Na(+) in yeast viability in acidic conditions was tested using S. cerevisiae Na(+)-ATPases (ena1-4), Na(+)/H(+) antiporter (nha1Delta) and Na(+)/H(+) antiporter prevacuolar (nhx1Delta) 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.
Sant'Ana
Gilzeane dos Santos
GS
Laboratório de Biologia Celular e Molecular (LBCM), Núcleo de Pesquisa em Ciências Biológicas, Departamento de Farmácia, Instituto de Ciências Exatas e Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, MG, Brazil.
Paes
Lisvane da Silva
LS
Paiva
Argentino F Vieira
AF
Fietto
Luciano Gomes
LG
Totola
Antônio Helvécio
AH
Trópia
Maria J Magalhães
MJ
Silveira-Lemos
Denise
D
Lucas
Cândida
C
Fietto
Juliana L Rangel
JL
Brandão
Rogelio L
RL
Castro
Ieso de Miranda
IM
D000143:Acids / Q000494:pharmacology*; D000935:Antifungal Agents / Q000494:pharmacology*; D016923:Cell Death; D017353:Gene Deletion; D005800:Genes, Fungal; D006863:Hydrogen-Ion Concentration; D007477:Ions / Q000378:metabolism*; D050296:Microbial Viability; D017494:Proton Pumps / Q000378:metabolism; D012440:Saccharomyces / Q000187:drug effects* / Q000502:physiology*; D013312:Stress, Physiological
D000143:Acids; D000935:Antifungal Agents; D007477:Ions; D017494:Proton Pumps