GENETIC DIVERSITY OF LACTOBACILLI ISOLATED FROM HUMAN INFANT FECES*

Abstract

Seventy-five strains isolated from fecal samples of six children were studied for their morphology and biochemical properties. Genetic diversity of 30 strains was analyzed by using Random Amplified Polymorphic DNA (RAPD). The intestinal isolates were grouped into four clusters. Some strains in group I were 100% similar (Lactobacillus reuteri) while high degree of genetic diversity was found in groups II (standard species), III and IV. Eight strains of group I and group III were identified through biochemical identification, as Lactobacillus reuteri, Lactobacillus acidophilus, Lactobacillus plantarum, Lactobacillus casei and Lactobacillus salivarius, and showed low genetic similarity with type strains. The findings in this study provide a strong basis for exploring the potential of these eight selected lactobacilli strains for use in fermented-milk based products.