Influence of Selected Factors on Biofilm Formation by Salmonella enterica Strains

Biofilm formed by S. enterica on the surface of gallstones or biomaterials promotes the development and spread of chronic infection. The aim of the study was to assess biofilm formation on the surface of polystyrene depending on nutritional conditions and the effect of 0.5, 1.0, and 2.0% glucose and 3.0% bile and sub-inhibitory concentrations of ampicillin on biofilm formation of S. enterica. Sixty-nine clinical strains of S. enterica isolated from feces (92.8%) and blood (7.2%) collected from patients (66.7%) and carriers (33.3%) were used in the study. Assessment of forming 24-h biofilm by these strains was performed on the surface of polystyrene 96-well plates at 37 °C. In this study, it was indicated that 1.0% glucose and 3.0% bovine bile inhibit biofilm formation. Biofilm formation was inhibited in all examined sub-MIC of ampicillin. Biofilm formation is varied in different conditions, depending on the serovar.

Effect of lactic acid fermentation on the quality of brewer's spent grain as ruminant feed

Brewer's spent grain (BSG) was used in this study as a support for the immobilization of Lactobacillus paracasei NRRL B-4564, thus enabling the recirculation of immobilized biomass in repeated-batch fermentation. The chemical composition and the energy parameters of the fermented and non-fermented BSG were analyzed and compared. Moreover, the probiotic features of L. paracasei were analyzed to examine the possibility of using fermented BSG as a functional ingredient in ruminant diets. The results obtained indicate that the fermented BSG had significantly higher protein and ash contents, as well as a significantly lower content of fiber fractions. Furthermore, the fermentation process increased the BSG energy content. The analysis of probiotic potential revealed a high tolerance of L. paracasei to pH 2.5 and bovine bile, autoaggregation ability and antimicrobial activity, suggesting that the fermented BSG with immobilized microbial biomass can be used as functional feed in ruminant diets.