Molecular Characterization of Egyptian Isolates of Lactobacillus and Bifidobacterium

Strains of Lactobacillus and Bifidobacterium were isolated from processed milk collected in Cairo, Egypt. Lactobacilli was isolated on Acetate media (SL) of Rogosa and Mitchell-Weisman. While Bifidobacterium was isolated on DSM medium (Difco Sporulation Medium). The isolates were characterized microscopically, morphologically and by some biochemical tests. DNA was extracted from the specified isolates using (Qiagen, Germany. Cat #51306) and species-specific primers for Lactobacillus and Bifidobacterium were designed to amplify the 16s rDNA gene as a conserved region in the bacterial DNA. Elution of the target band from the gel was performed efficiently and the 16S rDNA region was subjected to sequencing using Sequencer ABI PRISM 3730XL Analyzer. The sequencing data obtained suggested that the two studied isolates were (at the genus level) designated as Lactobacillus and uncultured Bifidobacterium. When the sequencing data was aligned on http://www.ncbi.nlh.nih.gov, it shows 88% homology and expected value of 7e-164 to Lactobacillus kiranofaceins but dendogram tree shows more homology to Lactobacillus plantarum family. While the other sample showed 91% homology and expected value of 3e-113 with Uncultured Bifidobacterium Clone R333 16S rRNA gene. (Hashem S.; H. H. Sabit; M. Amin; W. Tawakkol; and A. F. Shamseldin. Molecular Characterization of Egyptian Isolates of Lactobacillus and Bifidobacterium. Journal of American Science 2010;6(11):959-964). (ISSN: 1545- 1003).