engleski

Surface proteins of probiotic strain Lactobacillus paraplantarum SF9B: Effect of simulated conditions of the gastrointestinal tract

Autochthonous strain Lactobacillus paraplantarum SF9B, isolated from traditionally produced sour cabbage, expresses numerous advanced probiotic features. Besides high autoaggregation ability, this strain shows high capacity of adhesion to mucin and to extracellular matrix proteins fibronectin and collagen. L. paraplantarum SF9B cells can survive exposure to simulated conditions of the gastrointestinal tract (GIT), as well as the process of freeze-drying. However, all the named properties are negatively affected by the removal of S-layer proteins from the cell surface using 5M guanidine hydrochloride (GHCl). Since survival in GIT is the most important prerequisite for exertion of probiotic activity, the effect of the exposure of L. paraplantarum SF9B cells to simulated conditions of GIT, precisely, simulated gastric and small intestine juices, to the composition of surface proteins of SF9B cells, was investigated using 2D-electrophoresis and mass spectrometry. It was discovered that after incubation of L. paraplantarum SF9B cells in simulated gastric juice, most of the cell surface proteins, including S-layer proteins, can not be detected. However, the layer of S- proteins is reestablished after incubation of the treated cells in simulated small intestine juice. This strongly indicates that S-layer proteins have an important role in physiology of L. paraplantarum SF9B and that they are an essential factor of probiotic activity of that strain.

surface proteins ; Lactobacillus paraplantarum ; simulated GIT conditions

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