Molecular Identification of Potentially Probiotic Lactobacilli

Abstract

The rRNA-targeted oligonucleotide probes are useful for the identification of Lactobacillus acidophilus, L. gasseri, L. johnsonii, L. crispatus, and L. amylovorus. However, the oligonucleotide probe designed for L. helveticus hybridized with nucleic acids of type strains of L. gallinarum and L. helveticus. Hence, the similarity among the 73 strains of lactobacilli was evaluated on the basis of their randomly amplified polymorphic DNA (RAPD) profiles derived from five single-primer reactions. These strains were grouped into seven clusters at a similarity level of 30%, which corresponded to six separate species of the L. acidophilus complex (L. johnsonii, L. gallinarum, L. amylovorus, L. crispatus, L. acidophilus, and L. gasseri, respectively) and L. helveticus. For the first time, strains of L. gallinarum were characterized by RAPD and PFGE analyses. The genome length in that species was estimated to be near 1.45 Mb with the summation of ApaI fragments, and near 1.95 Mb with the summation of SmaI fragments.

Characterization of the Lactobacillus casei Group and the Lactobacillus acidophilus Group by Automated Ribotyping

“…Recently, molecular finger- printing methods have been approached for the classification of lactobacilli (7,9,19,22). These molecular techniques, however, did not meet the following criteria (I6): (a) be cheap and time efficient; (b) generate multiple, independent markers; (c) provide adequate resolution of genetic differences; (d) be replicable; and (e) use extremely small samples.…”

“…The Lactobacillus casei group and the L. acidophilus group are of considerable industrial and medical interest because these groups are believed to play an important role in human health and nutrition by their influence on the intestinal flora (12,19 The L. acidophilus group also comprised only one species, L. acidophilus, but divided into six species as follows by DNA-DNA hybridization analysis: (13) and L. johnsonii (8). Because phenotypic characteristics between strains belonging to this group are very similar, it was difficult to identify and classify them by morphological and biochemical methods.…”

Analyses of Dynamics in Dairy Products and Identification of Lactic Acid Bacteria Population by Molecular Methods

“…rhamnosus (Tynkkynen et al, 1999), Lb. acidophilus (Roy et al, 2000), Lb. helveticus (Lortal et al, 1997), and Lb.…”

Characterisation and differentiation of lactobacilli by lectin typing

“…Traditionally, based on metabolic pathways, the genus has been divided into three groups [6], which do not correlate with 16S rRNA phylogeny. Previous investigations have used many genotype-based typing systems to characterise and to group lactobacilli [7,8]. However, classical phenotypic characterisation remains important for discerning groups of strains based on their common properties.…”