Studies on the Broad Spectrum Bioactivity of Probiotic Bacterium Lactobacillus delbrueckii

Abstract

Human vagina contains Lactobacilli that form part of the vaginal microbiota. The unique properties of the Lactobacillus species found in the vagina of healthy women allow us to find out the best dietary probiotic species. This study aimed to isolate and identify the Lactobacillus species from the vagina of healthy women to evaluate its dietary probiotic and antimicrobial properties. Out of eight Lactobacillus isolates, L. delbrueckii was selected because it showed more potent antibacterial property when compared to other seven species. From the 150 specimens collected, 90 strains were isolated. Among the 90 strains, Lactobacillus species were the predominant micro-organisms (63) followed by Candida species (11), Staphylococcus species (8), Micrococcus species (4), Enterococcus species (2) and Escherichia coli (2). Out of 63 Lactobacillus species isolated, L. delbrueckii (26) was the predominant bacterium isolated followed by L. plantarum (14), L. acidophilus (13), L. fermentum (2), L. rhamnous (2), L. salivarius (2), L. crispatus (2) and L. reuteri (2). newlineFurther, an effective low-molecular weight (14.3KDa) anti-microbial peptide, bacteriocin was purified from the cell-free supernatant of L. delbrueckii. MALDI TOF investigation was also performed to confirm the molecular weight of bacteriocin. The isolated bacteriocin was proteolytic enzyme-sensitive, heat resistant and stable over a wide range of pH. newline