Figure 2.

Phylogenetic tree of the anammox bacterial 16S rRNA genes retrieved from Shengli Oilfield (shown in boldface) and the referred sequences in the EMBL database with the divisions listed to the right. The clones were designated by the sample name and the randomly picked clone series number. The topology shown was calculated with the neighbor-joining method. Bootstrap values (n = 1,000 replicates) of ≥50% were reported near the corresponding nodes. The scale bar represented 0.05 nucleic acid substitutions per nucleotide position. Planctomyces maris (AJ231184), Planctomyces limnophilus (X62911), and Nitrosomonas europaea (AF353160) were used as out-groups