FIG. 1.

Neighbor-joining trees of the 16S rRNA gene sequences obtained from communities of Bacteria (A) and Archaea (B) from the Rio Tinto rhizosphere (shown in boldface type) and all other closest representative sequences obtained from the ARB database, which are given with their GenBank accession numbers. OTUs were defined based on 97% sequence similarity. The total number of identical to nearly identical sequences (>97% similarity) to each OTU is indicated in brackets. Bootstrap values above 50% are indicated at the nodes. The scale bar below the tree corresponds to 0.1 substitutions per nucleotide for a unit branch length. Bacterial and archaeal trees were rooted with Methanococcus thermolithotrophicus and Planctomyces maris, respectively. PCB, polychlorinated biphenyl. RCP, reject coal pile.