INVESTIGADORES
PEREZ Pablo Fernando
artículos
Título:
Lactobacilli isolated from kefir grains: evidence of the presence of S-layer proteins.
Autor/es:
GARROTE, G. L.; DELFEDERICO, L.; BIBILONI, R.; ABRAHAM, A. G.; PÉREZ, P. F.; SEMORILE, L.; DE ANTONI, G. L.
Revista:
Journal of Dairy Research
Referencias:
Año: 2004 vol. 71 p. 222 - 230
ISSN:
0022-0299
Resumen:
In the present study we report for the first time the presence of S-layer proteins in Lactobacillus
kefir and Lactobacillus parakefir isolated from kefir grains. Soluble whole-cell protein profile
obtained either by mechanical disruption (X-press) or by a combined treatment with lysozyme
and SDS on whole cells, showed a significant band of apparent molecular mass of 6671 kDa
as measured by SDSPAGE. The intensity of this band was considerably reduced when cells
were treated with 5 M-LiCl. The above mentioned proteins were recovered in the LiCl extracts.
After dialysis and concentration, the proteins extracted were able to reassemble in a regular
array. Negative staining of these protein preparations were analysed by transmission electron
microscopy and a paracrystalline arrangement was seen. Thin sections of bacteria analysed by
transmission electron micrographs showed an outermost layer over the bacterial cell wall, that
was lost after the LiCl treatment. The production of this surface structure under different culture
conditions was also evaluated. Finally, the relationship between the presence of S-layer proteins
and surface properties (e.g. adhesion to Caco-2 cells, autoaggregation, and hemagglutination)
was investigated.