Influence of bile on beta-galactosidase activity and cell viability of Lactobacillus reuteri when subjected to freeze-drying.
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.
de Valdez
G F
GF
Centro de Referencia para Lactobacilos (CERELA), Tucumán, Argentina.
Martos
G
G
Taranto
M P
MP
Lorca
G L
GL
Oliver
G
G
de Ruiz Holgado
A P
AP
D001646:Bile / Q000502:physiology*; D005612:Freeze Drying; D007778:Lactobacillus / Q000201:enzymology* / Q000502:physiology*; D001616:beta-Galactosidase / Q000378:metabolism*
D001616:beta-Galactosidase