Selection of probiotic strains and development of green tea based probiotics for livestock

Twenty six (26) strains of Lactobacillus acidophilus, Lactobacillus plantarum, Lactobacillus casei, Enterococcus faecium, Bacillus subtilis, Bacillus coagulans, andSaccharomyces cerevisiae from Korean Collection for Type Cultures (KCTC) were evaluated in this experiment for the development of green tea based probiotics production and their inhibition effect against pathogenic bacteria was examined. The strains were first tested for acid and bile tolerance, and the higher tolerance strains were subsequently analyzed for heat tolerance and susceptibility to green tea extracts. Among the tested strains, L. acidophilus KCTC 3111, L. plantarum KCTC 3104, B. subtilis KCTC 3239, B. coagulans KCTC 1015, and S. cerevisiae KCTC 7915 which displayed a high tolerance to acid, bile, and heat, and no susceptibility to green tea extract, were selected to produce fermented green tea probiotics. Associative effects of green tea probiotics andEscherichia coli S93 F5, S99 LT, S170 F41, and S171 F6 revealed that E. coli numbers had gradually decreased compared to the control. Stability results of Lactobacillus spp. and Bacillus spp. in green tea probiotics showed that they were stable at 108 CFU/g during eight weeks of storage. Therefore, it is expected that green tea probiotics may provide a potential feed additive for livestock.   Key words: Green tea, probiotics, tolerance, E. coli, feed additive, livestock.