FIG. 6.

Phylogenetic relationships of strain MLHE-1 based on phylogenetic analysis of its 16S rRNA gene sequence. Aerobic As(III) oxidizers, as summarized by Santini et al. (34), are in boldface, and the tree includes the chemoautotrophic strains of the α-Proteobacteria related to the genus Agrobacterium and the heterotrophic strains of the β-Proteobacteria related to the genus Alcaligenes (30). The tree is unrooted, with Halobacterium salinarum as the outgroup. Numbers adjacent to nodes indicate bootstrap support for the branch (100 iterations; values of <50 are not shown), and the bar at the bottom indicates the number of nucleotide substitutions per position.