About 20 μl of the PCR product were analyzed by electrophoresis in a 1% agarose gel (Sigma, USA) with 0.5× TBE buffer (Sambrook et al., 1989) at 150 V for 45 min. DNA markers of Fermentas were used as control. The bands were excised from the gels and purified using GenElute Minus EtBr Spin Columns (Sigma). Sequencing procedure of purified fragments of 16S rDNA was made as described by Sanger et al. (1977), using the 35S-labeled dATP and a CEQ DTCS kit (Beckman Coulter, FRG). For partial nucleotide sequencing 926R primer was used. Standard procedures recommended by the manufacturer Beckman Coulter were performed on the automatic sequenator CEQ-8000.