PHYLOGENY OF THE GENUS CHLOROBIUM BASED ON 16S RDNA SEQUENCE

A comparative analysis of 16S ribosomal DNA sequences from 18 strains belonging to different species of the genus Chlorobium has been made i n order to investigate their phylogenetic relationships. All studied s trains with brown pigmentation, belonging to species C. phaeobacteroid es and C. phaeovibrioides, were clustered together and separated from green species. Most of the C. limicola strains formed a consistent gro up and were clustered next to C. tepidum. But, despite their identical morphology, C. vibrioforme strain 6030 (=DSM 260(T)) and C. vibriofor me strain 8327 (=DSM 263) were clearly differentiated on the basis of their 16S rDNA sequence. On the other hand, morphologically distinctiv e strains of C. chlorovibrioides, C. vibrioforme and C. limicola prese nted sequences with a high degree of similarity. Since morphological c haracters do not seem to be sufficient to adequately classify this gro up, these findings help to set up the basis for a revision of the taxo nomy of the genus Chlorobium.