INVESTIGADORES
FADDA Silvina Graciela
congresos y reuniones científicas
Título:
Proteomic analysis to unravel bile acid response of a probiotic Lactobacillus reuteri strain
Autor/es:
BUSTOS AY; FONT, G.; FADDA S; MOZZI, F; RAYA, R; TARANTO, MP
Lugar:
Amsterdam
Reunión:
Simposio; 10th International Symposium on Lactic Acid Bacteria; 2011
Institución organizadora:
Federation of European Microbiological Societies and the Nether lands Society for Microbiology
Resumen:
Lactobacillus reuteri is an established probiotic agent; the most widely distributed Lactobacillus speciesamong mammalians. The ability of L. reuteri to survive passage through the intestinal tract is a key pointrelated to its probiotic function. Aiming at unraveling the molecular basis of the adaptive mechanism ofL. reuteri CRL1098 to bile acids (BA), a proteomic approach was carried out. Protein expression of L.reuteri CRL 1098 growing in the presence of BA (glycodeoxycholic; GDCA or deoxycholic; DCA) wasevaluated using bidimensional electrophoresis and mass spectrometry. A delay in bacterial growth wasobserved only when cells were challenged with DCA. Proteomic data showed that in the presence ofGDCA, 14 proteins related to amino acid and nucleotide metabolisms, transcription and translation and pH homeostasis were overexpressed. Although 8 proteins involved mainly in lipid metabolism weresynthesized in lower amounts. When L. reuteri CRL1098 was grown in the presence of DCA, 13proteins, including chaperones and enzymes from amino acid pathways were up-regulated, while 15from nucleotide synthesis, energetic and lipid metabolisms were under-shifted. The better adaptationobserved in the presence of GDCA could be related to an improved pH homeostasis due to theoverexpression of GTP-binding protein TypA and nucleotide metabolism proteins such as CTPsynthetase. On the contrary the later was underexpressed in DCA growing conditions. The stronger harshenvironment produced by DCA is reflected by the overexpression of a typical stress proteins such aschaperone GroEL Results showed that bile salts induce a complex physiological response in L. reuteriCRL 1098, this study contributing with new insights in the mechanisms underlying the capacity ofintestinal lactobacilli to tolerate bile stress.