Molecular Typing by Genus-Specific PCR and Rapd Profiling of Diverse Lactobacillus Delbrueckii Strains Isolated from Cow, Sheep and Buffalo Yoghurts

ABSTRACT

A collection of twenty Lactobacillus strains isolated from yoghurts coming from different sources, and determined as Lactobacillus delbrueckii by morphological, physiological and biochemical tests (13), was subjected to PCR-based methods for typing. They were screened by two sets of Genus-specific PCR (GS-PCR) primers which confirmed their affiliation to the genus Lactobacillus. Although these dairy bacteria belong to the same species, some of them which were studied in a previous research (4) showed a few differences in their growth characteristics, probably reflecting their relatedness. In this study their phylogenic divergence was further investigated by randomly amplified polymorphic DNA (RAPD) analysis using ten different oligonucleotide primers.

Keywords:

• Lactobacillus delbrueckii
• polymerase chain reaction
• randomly amplified polymorphic DNA analysis