Isolation and Characterization of Lactobacillus Strains with Probiotic Potential from Dairy Products

Aims: This research aims to isolate and characterize from dairy products, in particular yogurts, cultivated Lactobacillus strains with potential for use as probiotics in poultry farming. Study Design: This research consists of four parts, an introduction with literature review, a description of the materials and methods used, finally the results obtained and their discussion. Place and Duration of Study: Central Veterinary Laboratory of Kinshasa, specifically in the Bacteriology and Animal Services departments, between April and September 2022. Methodology: A yogurt was cultured in order to observe the presence of Lactobacilli in the MRS (Mans, Rogosa and Sharp) Agar culture medium; this culture revealed the growth of Lactobacilli. It was even proceeded to the serial dilution of these strains, the results had also revealed the growth of Lactobacilli in the 6 test tubes used. Results: The results obtained showed a significant increase in weight (positive effect on the immune system) in the poultry of the experimental group and an absence of pathogenicity after an incubation period (inhibitory effect of strains of Lactobacilli on those of Escherichia coli and Streptococcus sp.) whereas in the control group, the poultry showed a lower weight gain compared to the experimental group and developed colibacillosis associated with other effects such as weakness, fever and angina after an incubation period. Conclusion: The positive results of Lactobacilli strains obtained in poultry in the experimental group show the potential of these strains to be used as probiotics in poultry farming to improve poultry health through the inhibitory effect of these strains on pathogenic Escherichia coli and Streptococcus sp. This opens up safe alternatives to the use of these strains to fight the misuse of antibiotics by reducing their use in human and animal care.