title: Influence of bile on beta-galactosidase activity and cell viability of Lactobacillus reuteri when subjected to freeze-drying.
abstract: The effect of bile on beta-galactosidase activity and cell viability was investigated using two strains of Lactobacillus reuteri that were subjected to freeze-drying. In the presence of 0.15% oxgall, beta-galactosidase activity of the whole cells was significantly increased. After lyophilization, the cultures that had been treated with oxgall showed a low survival rate without changes in beta-galactosidase activity. The poor resistance of the cells to damage from freeze-drying might be related to the presence of membranous structures containing simple folds and buds of the cell membrane, as was observed by transmission electron microscopy.
authors.affiliation: Centro de Referencia para Lactobacilos (CERELA), Tucumán, Argentina.
authors.forename: G F
authors.initials: GF
authors.lastname: de Valdez
authors.forename: G
authors.initials: G
authors.lastname: Martos
authors.forename: M P
authors.initials: MP
authors.lastname: Taranto
authors.forename: G L
authors.initials: GL
authors.lastname: Lorca
authors.forename: G
authors.initials: G
authors.lastname: Oliver
authors.forename: A P
authors.initials: AP
authors.lastname: de Ruiz Holgado
mesh_terms: D001646:Bile / Q000502:physiology*; D005612:Freeze Drying; D007778:Lactobacillus / Q000201:enzymology* / Q000502:physiology*; D001616:beta-Galactosidase / Q000378:metabolism*
chemical_list: D001616:beta-Galactosidase