Biofilm Formation in the Case of Lactobacillus sp. Il2

Abstract

SUMMARY The study uses a probiotic strain, Lactobacillus sp. IL2, to highlight exopolysaccharides synthesis and the formation of b iofilm so as to obtain a product that can be used in the control of human intestinal microflo ra. [1] The recent studies show that the structure and dynamics of the biofilm vary accordin g to the strains it is composed of, as well as to the surface on which it attaches and the nutr itional factors. The exopolysaccharides also play a determinative role in the capacity of biofil m formation through their structure. [2] The impact of the environmental factors on the capacity to form biofilm was tested. Therefore, in order to highlight this link, polysaccharides were isolated through ethanol precipitation. The testing of the capacity to form biofilm was made th rough monitoring the adhesion to a abiotic surface. The capacity of biofilm formation as well as exopolysaccharides’synthesis, are highly influenced by the growth conditions of the strain. From the data obtained, it results that glucose determines a maximum synthesis of exopolysaccharides, as well as a maximum capacity to form biofilm, compared to the usage of lactosis or sucrose. A reduced pH, high quantities of salt, the presence of mucin or biliar y salts influence this capacity in different ways. Biliary salts with a concentration lower than 1% have a positive effect, significantly stimulating this capacity, while the presence of Na Cl and of mucin does not have a significant importance, compared to the standard environment MRS ‐ glc. The same characteristic can be also noticed in the case of exopolysaccharides synt hesis. Comparing the data obtained and the data from literature it can be concluded that the s train can be used to produce functional probiotic products, with role in the modulation of human intestinal micro-flora.