The probiotic potential of lactobacilli isolated from Nile tilapia (<i>Oreochromis niloticus</i>)’s intestine

Abstract

The potential probiotic acid lactic bacteria isolated from Nile tilapia (Oreochromis niloticus)fs intestine was tested for fish farming. In our collection, 10 Lactobacillus strains were targeted to confront a series of antibiotics in order to draw their resistance profile, and to test their degree of inhibitory to four pathogenic bacteria, Staphylococcus aureus, Escherichia coli, Streptococcus sp. and Pseudomonas sp. The power of acidification and tolerance was tested. Overall, our results show that strains BLT31 and BLT21 are fully susceptible and resistance to the tested antibiotics. Strains BLT3, BLT20, BLT21 and BLT23 have a good antagonistic effect against pathogenic bacteria that cause the highest damage in aquaculture. For acid lactic production, strains BLT3, BLT26, BLT27, BLT28, and BLT31 are considered fast since Ģ pH . 4U in less than three hours. As for the resistance to pH and bile salts, two strains BLT3 and BLT31 showed significant power which gives them acceptable probiotic potential.

Key words: Probiotics, antibiotics, aquaculture, the Nile Tilapia, inhibitory activities, lactobacilli.