2.3. Amplification and sequencing of 16S rDNA gene
Amplification of the 16S rDNA gene (1500 bp) was performed
using specific primers for Lactobacillus and Lactococcus genus (F: 50-
AGAGTTTGATCMTGGCTCAG-30 and R: 50-TACCTTGTTAGGACTTCACC-
30). The PCR program cycle was set as follows: denaturation
for 4 min at 95 C, 32cycles for 5 min (which consisted of 94 C for
1 min, 58 C for 1 min, and 72 C for 95 s), and a final extension at
72 C for 5 min. Amplicons were electrophoresed on 1% agarose gel.
The amplified fragment was then purified from the gel using a
QIAquick PCR purification kit (QIAGEN, Hilden, Germany). Purified
16S rDNA fragments were sequenced by Macrogene Company
(Korean sequencing company). Each sequence was blasted with deposited sequences in GenBank, NCBI site
to molecularly identify each strain.