Cloning of a novel specific SCAR marker for species identification in Lactobacillus pentosus

[[abstract]]Identifying Lactobacillus species using only phenotypic and genotypic (16S rDNA sequence analysis) techniques yields inaccurate results. The objective of this study was to develop species-specific primers based on randomly amplified polymorphic DNA (RAPD) fingerprinting to distinguish species within the closely related Lactobacillus plantarum group. One of these primers, OPD-3, produced a species-specific band that was found only in the tested L. pentosus. This specific fragment was isolated from agarose gel and ligated into a vector for DNA sequencing. A pair of primers, SpOPD3Lpen-F1/R1, that were highly specific sequence-characterized-amplified-regions (SCARs) were designed according to the nucleotide sequences of the specific RAPD marker. These primers were used for PCR analysis of the template DNA of the Lactobacillus strains, and a single 542 bp species-specific band was found only in Lactobacillus pentosus. Using PCR, a novel species-specific primer pair is shown to rapidly, accurately and effectively distinguish L. pentosus from other species in the L. plantarum group of probiotic bacteria