Phylogenetic tree of 16S rDNA of low frequency Clostridium sp. (unsegregated) and Framework sequences. A neighbor - joining analysis with Jukes-Cantor correction and bootstrap support was performed on the rrs sequences of low frequency Clostridium sp. - 83 (shown in red) (which could not be segregated among the 15 known Clostridium sp. known to occur at high frequency) along with 56 of phylogenetic framework (Figure 1). Bootstrap values are given at nodes. Sequences marked by filled square are the ones considered as framework in the study whereas type strains are indicated by 'T' as superscript. Values in parentheses are accession numbers (RDP and NCBI) (http://rdp.cme.msu.edu/ and http://www.ncbi.nlm.nih.gov/).