The purified DNA was used as the template for amplification of the full-length
16S rDNA using bacterial specific primers BSF8/20 and REVB with DyNAzyme
EXT DNA polymerase (Finnzyme, Espoo, Finland), according to Kanokratana et
al. [17]. The PCR products were gel-purified using a QIAGEN Gel Extraction kit,
ligated to pTZ57R/T vector (Fermentas, Vilnius, Lithuania) and transformed into
Escherichia coli DH5 by the heat-shock method [18]. Transformants were selected
on Luria-Bertani agar plates containing ampicillin (100g/ml), supplemented
with 40g/ml 5-bromo-4-chloro-3-indolyl--d-galactopyranoside (X-GAL) and
20g/ml isopropyl--d-thiogalactopyranoside (IPTG). 96 sequences of 16S rDNA
inserts were grouped according to restriction fragment length polymorphisms
(RFLP), determined from the DNA patterns obtained by agarose gel electrophoresis
after RsaI and HhaI digestion.