| Lactobacillus rhamnosus is a probiotic, gram-positive facultatively anaerobic bacterium that produces lactic acid as a major metabolic end product of carbohydrate fermentation. Several probiotic species are known to produce proteinaceous substances called bacteriocins. Bacteriocins act as growth inhibitory agents for closely related bacterial strains. Lactobacillus rhamnosus LCS742 has growth inhibitory activity against gram positive bacteria due to the production of a potential bacteriocin. Lactobacillus rhamnosus GG also displays antimicrobial activity against gram positive bacteria. We used the National Center for Biotechnology Information (NCBI) website to perform a search for the gene sequence of a bacteriocin in Lactobacillus rhamnosus GG. A gene sequence of a prebacteriocin was found in Lactobacillus rhamnosus GG, Lactobacillus rhamnosus ATCC 53103 with 100% identity and in Lactobacillus rhamnosus ATCC 8530, Lactobacillus rhamnosus Lc 705, with 95% identity. It was hypothesized that this gene of bacteriocin was also present in Lactobacillus rhamnosus LCS742. This study showed that activity of Lactobacillus rhamnosus LCS742 against gram positive bacteria is due to a proposed bacteriocin different from that of Lactobacillus rhamnosus GG. |
