Evaluation of probiotic characteristics and intraspecific diversity of Lactobacillus plantarum strains isolated from different foods by RAPD-PCR

The aim of this study was to evaluate the intra-species diversity of 10 strains of Lactobacillus plantarum isolated from different foods including fermented olives, jar cheese, camel milk and sourdough using RAPD-PCR method also to compare their probiotic potential. The results showed that different banding patterns were created by three types of primers for different strains and according to the similarity matrix drawn by NTSYS software based on Jacard coefficient, a total of 10 strains were divided into two main branches and seven subgroups. The two strains of KAO 17 and KAO 64 isolated from fermented olives were most similar. In addition, the probiotic properties of L. plantarum isolates were evaluated different at strain levels. The results of immunoassay showed that all different strains of L. plantarum were gamma-hemolytic and resistant to vancomycin and their resistance to other common antibiotics was different. Strains isolated from jar cheese containing KMC 37 and KMC 45 had the highest acid resistance. On the other hand, resistance to 0.3% of bile salt showed that there was no significant difference in this regard between the strains isolated from fermented olives and the KMM 5 strain had the highest resistance. In addition, the antimicrobial activity of the strains against gram-positive pathogenic bacteria L. monocytogenes and gram-negative E. coli was different and the highest antibacterial activity belonged to the KMC 45 strain. Therefore, according to the intended purpose, each of the L. plantarum strains can be suggested as a probiotic culture in the food or pharmaceutical Industries.