For this analysis, 20 l of each 16S rDNA amplicon were digested for 3 h at 37C with 2.5 U HaeIII (Fermentas,Vilnius,Lithuania). The DNA restriction fragments were electrophoresed in 3% agarose gel containing ethidium bromide (50 ng/ml). The gels were photographed, and the fingerprints were compared visually.