FIG. 6.

Phylogenetic tree of nosZ quantitative PCR products obtained with the nosZ2 primers and of nosZ genes from reference strains. Fragments of 267 nucleotides from the quantitative PCR products and from reference strains were used to calculate the tree. The tree is based on distance matrix analysis and the neighbor-joining method. Bootstrap values greater than 700 from 1,000 replicate trees are reported at the nodes. The sequence of nosZ from Wolinella succinogenes served as an outgroup to root the tree.