Figure 2. Phylogenetic tree based on partial 16S rRNA gene sequences (approximately 450 bp in length) of clones (classified into phylum Bacteroidetes) retrieved in this study and sequences of representative Bacteroidetes isolates.

Numbers of clones retrieved from different libraries are shown in square brackets. The dominant phylotypes in Cs50 and Cs200 enrichments (HS40, HS41, and HS42) and the isolated strain (Flavobacterium sp. 200Cs-4) are highlighted in bold letters. Cytophaga hutchinsonii was used as an out-group. Bootstrap values (1,000 trials, only >50% are shown) are indicated at branching points. The bar indicates 2% sequence divergence. Accession numbers of Bacteroidetes isolates and clones are shown in parentheses.