Identification and antimicrobial activity of Lactobacillus strains of poultry origin

This study was developed as part of the process for the selection of Lactobacillus strains with possible probiotic activity. Their objectives were to identify isolated strains of the digestive tract of broiler chickens and to discover the production of antimicrobial substances in front of Gram-positive and Gram-negative bacteria for their selection as probiotic strains. Six bacterial isolates (C7, C10, C11, C19, C44 and C65) were identified from the 16S-23S intergenic region sequence of the ribosomal RNA. The production of antimicrobial substances of these strains was determined by the substance diffusion method in agar. All strains were identified as Lactobacillus salivarius and were capable of inhibiting growth in the bacteria used as indicators, mainly by acid production. The inhibition by the production of possible bacteriocins was only found in the C7, C19 and C65 strains in the presence of Escherichia coli . These results confirm the possible utilization of the studied bacteria as candidates to probiotic microorganisms. Key words: Lactobacillus spp., Lactobacillus salivarius, antimicrobial activity