The 16S rRNA genes were amplified using the forward primer
the PRBA338F with a GC clamp and the reverse primer PRUN518R
(Heuer et al., 1997). The 16S rRNA gene fragments were separated
by DGGE. The DGGE gel was performed on 8% polyacrylamide
gels with a 30–60% denaturant gradient. Prominent DGGE bands
were excised and the eluted DNA as templates was reamplified
as described above, followed by the second DGGE. The single
bands on the second DGGE were sequenced by a commercial
sequencing service. All sequences were used to search in the Gen-
Bank using BLAST-n tool. Alignment and phylogenetic analysis
of the DNA sequences were performed using the MEGA4 software.