In vitro fructooligosaccharide utilization and inhibition of Salmonella spp. by selected bacteria

In vitro experiments were conducted to determine: 1) inhibitory capacities of potential direct-fed microbial bacteria against Salmonella serotypes; and 2) the ability of Bifidobacterium bifidum, Enterococcus faecium, Lactobacillus casei, Lactococcus lactis, Pediococcus sp., and Salmonella spp. to grow in media containing fructooligosaccharides (FOS-50 or FOS pure formulation) as the only carbohydrate source. Thirteen bacteria (two strains of Bacillus coagulans, Bacillus licheniformis, Bacillus subtilis, B. bifidum, E. faecium, two strains of Lactobacillus acidophilus, L. casei, Pediococcus sp., Propionibacterium acidopropionici, P. jensenii, and Propionibacterium sp.) were tested for inhibition of six Salmonella serotypes (S. california, S. enteritidis, S. heidelberg, S. mission, S. senftenberg, and S. typhimurium) using a spot-the-lawn technique. Bifidobacterium bifidum, E. faecium, all lactobacilli, and Pediococcus sp. clearly inhibited growth of all Salmonella serotypes. In the growth experiments, E. faecium, L. lactis, and Pediococcus sp. grew in media with either FOS-50 or the pure formulation of FOS as the sole carbohydrate source. All tested Salmonella serotypes utilized FOS-50 for growth; however growth varied among the serotypes. In contrast, none of the Salmonella serotypes grew in media containing the pure formulation of FOS as the only carbohydrate source.