Bands of interest were excised from the DGGE gel using sterile scalpel blades and incubated overnight in 50 ml of sterile distilled water. . Five microlitres of the eluted DNA was used as a template for reamplification with primer set EB341F (no-GC-clamp) and U517R . The PCR products were ethanol precipitated to remove excess primers,resuspended in 50 ml of sterile distilled water and sequenced by GATC Biotech, Germany