The 16S rRNA genes were amplified with bacterial universal primers specific for eubacterial
16S rRNA gene (Forward, AGTTTGATCATGGCTCAG) and (Reverse,TTACCGCGGCTGGCA). The PCR (25l) contained 0.5l of each forward and reverse primer, 1.5mM of 10X Taq buffer (stock 20mM), 0.2mM (2.0l) of each deoxynucleotide (ddATP, ddGTP, ddCTP and ddTTP), 1unit of Taq DNA polymerase (5units/l) and 1.5l DNA. PCR conditions were as follows: initial denaturation at 95ºC for 5 min, followed by 30 cycles, each with 1 min denaturation at 95ºC, 1 min annealing at 55ºC and extension at 72ºC for 1 min, before a final extension at 72ºC for 5 min. The PCR products obtained from DNA extracted from the samples were first analyzed by electrophoresis in 1.5% agarose gel and
were stained with ethidium bromide and visualized under short-wavelength UV light.