Biological Probiotic Properties of Lactobacillus rhamonosus GG-4 Isolated from Infant Feces

Abstract

To develop probiotics, a kind of Lactobacillus sp. was isolated from infant feces. The bacterium was identified as Lactobacillus rhamnosus through 16S rDNA sequence analysis. The strain was a facultative anaerobe which grew better in aerobic conditions. The bacterium lowered the pH of the culture solution down to 2.4 during 48 hr in the MRS medium. The strain inhibited the growth of 6 pathogens-S. aureus, L. monocytogens, S. typhimurium, E. coli O-157, V. parahaemolyticus and P. aeruginosa. When the Lactobacillus were fed to chickens, along with commercial feed, for one month, amounts of H2S and NH3 in the feces of the chicken decreased to 50% and 70%, respectively, compared to those of control group chickens. Amounts of other bad smells such as (CH3)SH, (CH3)2S and (CH3)2S2 were not much different in the Lactobacillus-fed chickens compared to the control group. On the other hand, egg weights of the chickens fed Lactobacillus were higher by about 5±1 g than those in the control group.