FIG. 2.

Phylogenetic tree showing gene sequences from excised DT-DGGE bands relative to closely related reference species. Neighbor-joining, maximum likelihood, and parsimony trees were constructed using only >1,000-bp sequences with the Felsenstein correction method, after which DT-DGGE band sequences were added (∼550 bp) to each tree by parsimony. The consensus tree was constructed based on the merged topologies of the three trees. Dark shading, phylotypes showing increased relative intensity in anoxic (nitrate-amended) sulfidic incubation treatments; light shading; phylotypes showing increased relative intensity in oxic thiosulfate-amended incubation treatments; no shading (boxes), phylotypes showing decreased relative intensity in sulfide-rich anoxic incubation treatments.